Compiled WSJT-X from the latest source code on a Kubuntu 20.04 machine, connected to my (for me new) TS-2000. Everything works, except for the delay when e.g. double clicking a call in the band activity column, saving a log entry, selecting an audio device, etc. The entire WSJT-X window freezes for at least a couple of seocnds after which operation resumes as normal. Delay times differ from 2 seconds (FT-4) to 7.5 seconds (FT-8), 9.5 seconds (saving a log entry). I don't have the impression that the program stops working, it's just a delay in the UI.
I also tried other versions, like the stock one from the Kubuntu 20.04 (2.1.12), the lastest deb 2.4.0 and some of the beta versions, but they all suffer from the same delay. So I guess it is a (K)Ubuntu thing, but what? The command line doesn't give me any verbose messages.
Any hints or tips welcome. Been searching the web, but it seems no one has this problem, as I haven't been able to find any reference to this phenomenon.
73 de Hans