It's a Debian 12 LXC container and PI-hole is all and the only whats running there, No access to other LXC's. Also standard ext4 filesystem and as I told it's running after backup older version I mentioned in prior task fine again.
Your debug log shows two issues - while the first one may or not be the cause for the second one:
Your log contains a warning that the database was not closed properly. Maybe the container was restarted abruptly or something else happened that didn't allow the pihole-FTL process to handle the database correctly.
As a consequence of no. 1 above (or completely independent, we don't know yet), your database got locked. This prevented pihole-FTL from reading your gravity database resulting in many warnings in your /var/log/pihole/FTL.log. And - apparently - down the line also prevented it from accessing any query data at all.
Please try starting from a fresh database to eliminate a database corruption as cause using:
sudo service pihole-FTL stop
sudo mv /etc/pihole/pihole-FTL.db /etc/pihole/pihole-FTL_broken.db
sudo rm /etc/pihole/pihole-FTL.db*
sudo service pihole-FTL start
to get an experimental branch which allows controlling the WAL mode and, subsequently, turning it off.
FTL from this branch should be available in a few minutes. Until then, you'd get a harmless error during the checkout and nothing happens.
edit Wait, I just had another look into your debug log and see that you have non-empty setting for webserver.api.excludeClients and webserver.api.excludeDomains. We merged a feature last week that extended these options to also be effective for the Query Log:
Could you please check if editing these (e.g. via the web interface's settings -> all settings page) resolves the issue you are seeing? I see you are using a limited set but - maybe just maybe - if all your queries are either localhost or fritz.box, then this would easily explain what is happening here.
Yes, I have seen these in your debug log. My point is:
When you have localhost and fritz.box as clients to be excluded and all your queries either come from localhost or fritz.box (because you are using the DNS server of your FritzBox instead of distributing the Pi-hole as DNS server), then everything is behaving as expected.
The only bit that was not expected is that the functionality of these settings was extended to the Query Log.