MySQL Server has gone away "Error" but everything is online

My Icinga Web2 is showing a lot of these Errors for example when i go to Dashboard.

Can someone Help me please. I am a complete Newbie to Linux and ICINGA.

Server is a Debian: Linux icinga01 5.10.0-13-amd64 #1 SMP Debian 5.10.106-1 (2022-03-17) x86_64

The error comes from mysql. These are probably timeouts. Check this page for some settings to tweak: