Nextcloud very slow after moving

I moved my Nextcloud from a V-Server to a Server at my home following the official instructions. On the new server the instance is very slow now, opening the website takrs roundabout 25 seconds until the Dashboard is fully loaded. Files need 20 seconds, opening a note 10, tag view in Photos or Memories app also takes mir then 20 seconds.


Before I did the moving I test my system with a freshly Testcloud instance. This instance is still running acceptable fast - up to 5 seconds for Dashboard, 1-2 seconds for other apps, tags, and places view on Photos/Memories, are there without waiting. I also moved a smaller nextcloud instance from the same origin server to the same destination server without problems, this instance also has no problems.

Settings on the new machine are all the same for all three instances, identical vhosts settings… I don’t understand what’s wrong.

So after more then a weeks of research and testing I’m running out of options.
Seems I need to drop the old instance and migrate everything to a new one.
Or would it be possible to just reinstall the instance and keep the database and files?

Nextclouds are all 27.1.2, Ubuntu 22.04, Apache2, MariaDB, Redis, Php 8.2, 16 GB RAM, Intel i7 11th Generation…

On the Machine I also have one WordPress instance, one Mediawiki, Plex and Jellyfin running.