unix:/run/php/php8.1-fpm.sock:

Yes u have 8.1 as seen in the log...I use the version 8.3

I'm not saying this will solve your problem, but I had something similar and it helped me.

Personally, I think the whole problem is caused by Jerome's onlineTV module.

Thanks a lot @PavelS for your help. If these module causing a problem do you think we should disable them them completely if we want to use UNA-15, since Jerome is not updating them any more?

Yes, definitely turn it off, personally I would uninstall it completely.