diff --git a/server/lib/client-html.ts b/server/lib/client-html.ts
index 0142b248b..38697401a 100644
--- a/server/lib/client-html.ts
+++ b/server/lib/client-html.ts
@@ -12,7 +12,6 @@ import { HTMLServerConfig } from '@shared/models'
 import { buildFileLocale, getDefaultLocale, is18nLocale, POSSIBLE_LOCALES } from '../../shared/core-utils/i18n/i18n'
 import { HttpStatusCode } from '../../shared/models/http/http-error-codes'
 import { VideoPlaylistPrivacy, VideoPrivacy } from '../../shared/models/videos'
-import { isTestInstance } from '../helpers/core-utils'
 import { logger } from '../helpers/logger'
 import { CONFIG } from '../initializers/config'
 import {
@@ -231,7 +230,7 @@ class ClientHtml {
   static async getEmbedHTML () {
     const path = ClientHtml.getEmbedPath()
 
-    if (!isTestInstance() && ClientHtml.htmlCache[path]) return ClientHtml.htmlCache[path]
+    if (ClientHtml.htmlCache[path]) return ClientHtml.htmlCache[path]
 
     const buffer = await readFile(path)
     const serverConfig = await ServerConfigManager.Instance.getHTMLServerConfig()
@@ -303,7 +302,7 @@ class ClientHtml {
 
   private static async getIndexHTML (req: express.Request, res: express.Response, paramLang?: string) {
     const path = ClientHtml.getIndexPath(req, res, paramLang)
-    if (!isTestInstance() && ClientHtml.htmlCache[path]) return ClientHtml.htmlCache[path]
+    if (ClientHtml.htmlCache[path]) return ClientHtml.htmlCache[path]
 
     const buffer = await readFile(path)
     const serverConfig = await ServerConfigManager.Instance.getHTMLServerConfig()
diff --git a/server/lib/plugins/plugin-manager.ts b/server/lib/plugins/plugin-manager.ts
index 39e7f9a5b..1305f660f 100644
--- a/server/lib/plugins/plugin-manager.ts
+++ b/server/lib/plugins/plugin-manager.ts
@@ -277,6 +277,8 @@ export class PluginManager implements ServerHook {
       logger.info('Regenerating registered plugin CSS to global file.')
       await this.regeneratePluginGlobalCSS()
     }
+
+    ClientHtml.invalidCache()
   }
 
   // ###################### Installation ######################
@@ -419,6 +421,8 @@ export class PluginManager implements ServerHook {
     }
 
     await this.addTranslations(plugin, npmName, packageJSON.translations)
+
+    ClientHtml.invalidCache()
   }
 
   private async registerPlugin (plugin: PluginModel, pluginPath: string, packageJSON: PluginPackageJSON) {
@@ -473,8 +477,6 @@ export class PluginManager implements ServerHook {
   // ###################### CSS ######################
 
   private resetCSSGlobalFile () {
-    ClientHtml.invalidCache()
-
     return outputFile(PLUGIN_GLOBAL_CSS_PATH, '')
   }
 
@@ -482,8 +484,6 @@ export class PluginManager implements ServerHook {
     for (const cssPath of cssRelativePaths) {
       await this.concatFiles(join(pluginPath, cssPath), PLUGIN_GLOBAL_CSS_PATH)
     }
-
-    ClientHtml.invalidCache()
   }
 
   private concatFiles (input: string, output: string) {
diff --git a/server/tests/api/check-params/video-editor.ts b/server/tests/api/check-params/video-editor.ts
index 1fd22c497..5f5faf8fb 100644
--- a/server/tests/api/check-params/video-editor.ts
+++ b/server/tests/api/check-params/video-editor.ts
@@ -122,7 +122,10 @@ describe('Test video editor API validator', function () {
       })
 
       it('Should fail with an already in transcoding state video', async function () {
+        this.timeout(30000)
+
         const { uuid } = await server.videos.quickUpload({ name: 'transcoded video' })
+        await waitJobs([ server ])
 
         await server.jobs.pauseJobQueue()
         await server.videos.runTranscoding({ videoId: uuid, transcodingType: 'hls' })
diff --git a/server/tests/api/server/plugins.ts b/server/tests/api/server/plugins.ts
index 76d3e2481..8aa34fb15 100644
--- a/server/tests/api/server/plugins.ts
+++ b/server/tests/api/server/plugins.ts
@@ -95,15 +95,15 @@ describe('Test plugins', function () {
   })
 
   it('Should have the plugin loaded in the configuration', async function () {
-    const config = await server.config.getConfig()
+    for (const config of [ await server.config.getConfig(), await server.config.getIndexHTMLConfig() ]) {
+      const theme = config.theme.registered.find(r => r.name === 'background-red')
+      expect(theme).to.not.be.undefined
+      expect(theme.npmName).to.equal('peertube-theme-background-red')
 
-    const theme = config.theme.registered.find(r => r.name === 'background-red')
-    expect(theme).to.not.be.undefined
-    expect(theme.npmName).to.equal('peertube-theme-background-red')
-
-    const plugin = config.plugin.registered.find(r => r.name === 'hello-world')
-    expect(plugin).to.not.be.undefined
-    expect(plugin.npmName).to.equal('peertube-plugin-hello-world')
+      const plugin = config.plugin.registered.find(r => r.name === 'hello-world')
+      expect(plugin).to.not.be.undefined
+      expect(plugin.npmName).to.equal('peertube-plugin-hello-world')
+    }
   })
 
   it('Should update the default theme in the configuration', async function () {
@@ -113,8 +113,9 @@ describe('Test plugins', function () {
       }
     })
 
-    const config = await server.config.getConfig()
-    expect(config.theme.default).to.equal('background-red')
+    for (const config of [ await server.config.getConfig(), await server.config.getIndexHTMLConfig() ]) {
+      expect(config.theme.default).to.equal('background-red')
+    }
   })
 
   it('Should update my default theme', async function () {
@@ -228,45 +229,62 @@ describe('Test plugins', function () {
   })
 
   it('Should update the plugin and the theme', async function () {
-    this.timeout(90000)
+    this.timeout(180000)
 
     // Wait the scheduler that get the latest plugins versions
     await wait(6000)
 
-    // Fake update our plugin version
-    await server.sql.setPluginVersion('hello-world', '0.0.1')
+    async function testUpdate (type: 'plugin' | 'theme', name: string) {
+      // Fake update our plugin version
+      await server.sql.setPluginVersion(name, '0.0.1')
 
-    // Fake update package.json
-    const packageJSON = await command.getPackageJSON('peertube-plugin-hello-world')
-    const oldVersion = packageJSON.version
+      // Fake update package.json
+      const packageJSON = await command.getPackageJSON(`peertube-${type}-${name}`)
+      const oldVersion = packageJSON.version
 
-    packageJSON.version = '0.0.1'
-    await command.updatePackageJSON('peertube-plugin-hello-world', packageJSON)
+      packageJSON.version = '0.0.1'
+      await command.updatePackageJSON(`peertube-${type}-${name}`, packageJSON)
 
-    // Restart the server to take into account this change
-    await killallServers([ server ])
-    await server.run()
+      // Restart the server to take into account this change
+      await killallServers([ server ])
+      await server.run()
 
-    {
-      const body = await command.list({ pluginType: PluginType.PLUGIN })
+      const checkConfig = async (version: string) => {
+        for (const config of [ await server.config.getConfig(), await server.config.getIndexHTMLConfig() ]) {
+          expect(config[type].registered.find(r => r.name === name).version).to.equal(version)
+        }
+      }
 
-      const plugin = body.data[0]
-      expect(plugin.version).to.equal('0.0.1')
-      expect(plugin.latestVersion).to.exist
-      expect(plugin.latestVersion).to.not.equal('0.0.1')
+      const getPluginFromAPI = async () => {
+        const body = await command.list({ pluginType: type === 'plugin' ? PluginType.PLUGIN : PluginType.THEME })
+
+        return body.data.find(p => p.name === name)
+      }
+
+      {
+        const plugin = await getPluginFromAPI()
+        expect(plugin.version).to.equal('0.0.1')
+        expect(plugin.latestVersion).to.exist
+        expect(plugin.latestVersion).to.not.equal('0.0.1')
+
+        await checkConfig('0.0.1')
+      }
+
+      {
+        await command.update({ npmName: `peertube-${type}-${name}` })
+
+        const plugin = await getPluginFromAPI()
+        expect(plugin.version).to.equal(oldVersion)
+
+        const updatedPackageJSON = await command.getPackageJSON(`peertube-${type}-${name}`)
+        expect(updatedPackageJSON.version).to.equal(oldVersion)
+
+        await checkConfig(oldVersion)
+      }
     }
 
-    {
-      await command.update({ npmName: 'peertube-plugin-hello-world' })
-
-      const body = await command.list({ pluginType: PluginType.PLUGIN })
-
-      const plugin = body.data[0]
-      expect(plugin.version).to.equal(oldVersion)
-
-      const updatedPackageJSON = await command.getPackageJSON('peertube-plugin-hello-world')
-      expect(updatedPackageJSON.version).to.equal(oldVersion)
-    }
+    await testUpdate('theme', 'background-red')
+    await testUpdate('plugin', 'hello-world')
   })
 
   it('Should uninstall the plugin', async function () {
@@ -293,15 +311,15 @@ describe('Test plugins', function () {
   })
 
   it('Should have updated the configuration', async function () {
-    const config = await server.config.getConfig()
+    for (const config of [ await server.config.getConfig(), await server.config.getIndexHTMLConfig() ]) {
+      expect(config.theme.default).to.equal('default')
 
-    expect(config.theme.default).to.equal('default')
+      const theme = config.theme.registered.find(r => r.name === 'background-red')
+      expect(theme).to.be.undefined
 
-    const theme = config.theme.registered.find(r => r.name === 'background-red')
-    expect(theme).to.be.undefined
-
-    const plugin = config.plugin.registered.find(r => r.name === 'hello-world')
-    expect(plugin).to.be.undefined
+      const plugin = config.plugin.registered.find(r => r.name === 'hello-world')
+      expect(plugin).to.be.undefined
+    }
   })
 
   it('Should have updated the user theme', async function () {
diff --git a/shared/server-commands/server/config-command.ts b/shared/server-commands/server/config-command.ts
index e47a0d346..1dd6e1ea4 100644
--- a/shared/server-commands/server/config-command.ts
+++ b/shared/server-commands/server/config-command.ts
@@ -123,6 +123,21 @@ export class ConfigCommand extends AbstractCommand {
     })
   }
 
+  async getIndexHTMLConfig (options: OverrideCommandOptions = {}) {
+    const text = await this.getRequestText({
+      ...options,
+
+      path: '/',
+      implicitToken: false,
+      defaultExpectedStatus: HttpStatusCode.OK_200
+    })
+
+    const match = text.match('<script type="application/javascript">window.PeerTubeServerConfig = (".+?")</script>')
+
+    // We parse the string twice, first to extract the string and then to extract the JSON
+    return JSON.parse(JSON.parse(match[1])) as ServerConfig
+  }
+
   getAbout (options: OverrideCommandOptions = {}) {
     const path = '/api/v1/config/about'