According to https://bugs.kde.org/show_bug.cgi?id=409753 (which looks very much like your bug), reverting this commit should fix it:
https://cgit.kde.org/akonadi.git/commit/?id=74aed9542ba1ff1e6e93a550c42869647c4eba8e

No need for downgrading the whole package.

We don't necessarily need this change anyway, as we reverted the incompatible change in Qt.

Please try the package from here:
https://download.opensuse.org/repositories/home:/wolfi323:/branches:/KDE:/Applications/

The standard 19.04.3 works without problems here (with the default internal database), so I suppose it only affects external database connections...

yep, it does - right now my akonadi is using sqlite in a non-standard (local filesystem) location, sqlite on NFS is as bad an idea as mysql/postgresql on nfs is (which is why I had it set to do sql over tcp to my central database server).

Will try the stuff from your repo and report.

(In reply to Wolfgang Bauer from comment #2)
> Please try the package from here:
> https://download.opensuse.org/repositories/home:/wolfi323:/branches:/KDE:/
> Applications/
> 
> The standard 19.04.3 works without problems here (with the default internal
> database), so I suppose it only affects external database connections...

I tried the packages from your repository and that akonadiserver works with remote mysql just fine.

Ok, the new package is in KDE:Applications meanwhile, and has been forwarded to Factory.

https://build.opensuse.org/request/show/716045
https://build.opensuse.org/request/show/716146

akonadiserver just got upgraded back to the packages from KDE:Applications and I can confirm fixed.

*** Bug 1142680 has been marked as a duplicate of this bug. ***

This is an autogenerated message for OBS integration:
This bug (1141604) was mentioned in
https://build.opensuse.org/request/show/718315 Factory / akonadi-server