That’s hella beefy performance settings against the average load you have.
Looks a bit over the top. :x
Deadlocks can happen once or twice in a while. Especially taskbars can be an issue.
What might help is to update Zammad, clear its cache and try to reduce your taskbars.
If you haven’t already, consider using the filesystem as attachment storage to reduce your database servers load on serving binaries.
Dangerzone
Below command destroys ALL existing taskbars - this means DATALOSS if they’re drafts!
However, it allows a clean start with agents not having to cross out single tabs.
zammad run rails r "Taskbar.destroy_all"