Small sync button until window focus changed; sometimes with crash

[CoSoCo]

When I press the sync button, this button always resizes to a very small shape (see attachment). It redraws normal, when I change the focus to another window on the desktop. After that, sometimes the GUI freezes, continues all plugins, but often skips the remaining syncs. On next start, then the local files seen corrupt, as then the sync takes very long time once. And when running with jpilot -d, I can see a caught signal SIGCHLD message on the console.

I also see this crash sometimes without changing the window focus, but very rarely.

Seen on Ubuntu 22.04.

After focus change:

Sometimes I also see the caught signal SIGCHLDwhen operation seems to succeed without problem (see at the end of the log):
JPilot with signal SIGCHLD.log