I thought the patch would land on 5.15.3, but it seems it didn't
The issue is described at:
The patch, that applies cleanly over the current patches and is used in Debian for some time:
Thanks a lot
This should be put to invent.kde.org/qt then.
Closing this since 5.15.4 is in the process of being stabilised (and stable on amd64 already as of writing).