Musescore 4 - (USB) MIDI not working

Freshly released MuseScore 4 but the same old problems.
I have MuseScore 3 and it works. I mean MIDI input from and output to my Roland FP-30 works. Maybe not always from the start but I always manage to make it working.
I though that M4 will be better and will work from start without any problem.
It is somehow strange as the software is really outstanding but this very feature is a must and when it does not work it destroys all the positives.
There is another software for rookies like me - Synthesia. It cannot be compared with Musescore as it something else but it also has MIDI In and Out feature which works always without any problem.
Maybe it would be a good idea to ask its programmers for help with resolving this problem once and for all.
As I do not know how to solve the problem with MDI in MuseScore 4 I must stay by MuseScore 3.