At best remove those PHP 7.4 packages as well. They are as well from Ondrej’s repo and newer than the ones from Debian, keeping some other dependencies on the system which can cause issues. We can reinstall it later cleanly with a Nextcloud reinstall:
Thx for your support!
I am not shure but I think I must setup my DietPi from scratch again.
I have tried to perform a backup and Mount a share on my PC. I can see that DietPi writes the testfile. Neverthless he is not writing a backup - even the back tells me that it was successfull.
Last try is to fix the php issues. If this do not help at all I will setup dietpi with bookworm
Thx for your support. Finally I have setup the RasPi on Bookworm from scratch. In addition I found the failure in my backup (what I never noticed bfore): you need a NFS filesystem and not a samba share
However, one final question: when I adapt the apache2 config for the virtual host do I need for each port a seperate config or can I add them all to the nextcloud config?