Performance Issue on Nextcloud Office and same User shown Multiple Times

I have a Nextcloud Install behind an apache reverse proxy (not sure if it has anything to do with it) on an apache server. At first everything seems to work. But the Nextcloud Office seems to be sometimes unresponsiv, also I see that my Users aperas over and over again and I am logged in only once, on the top right I can see that my user aperas to be 28 times in the same document.

I am confused since I don’t see any errors, sometimes a short connecting apears inside the office document, where is the best way to look for answers to the problem? Since there are no error messages I don’t know where to start

Thank yo