Cannot use watch buttons when using XWiki in other language than english

Reproduction steps:

• Go to Administration > Content > Localization and set the wiki to use German
• Go the homepage and click on the watch button
• Try to select an option and save

Expected result:

• the watch filter is properly created

Obtained result:

• Nothing happens, the modal is reset and we can see in the browser console a 405 request error on:

  http://localhost:8080/xwiki/rest/wikis/xwiki/spaces/Main/pages/WebHome/translations/de/notificationsWatches?form_token=G1L5Y2JVxkJ146rKwDKSLA