Linux Pulseaudio MIDI keyboard

Hello. I am an old fan of best of one of the opensource apps Musescore, Thank you, all developers and all involved)
But somehow I missed MIDI input from midi keyboards (I tried it a loooong time ago and it was not easy task to make it work). But today, after that loooong time I tried to write composition with my piano.
I plugged in my Yamaha keyboard, started MuseScore, pressed "N", and I am not getting any notes from keyboard. Whatda?... Such old problem from Mesozoic Era still exists? In settings I see that default Pulseaudio backend is used. In online manuals and handbooks I didn't find anything about that with Pulseaudio you can't use MIDI keyboard.
Tried to dig myself in what is happening. In Konsole command "aconnect -o" showed me only "Midi Through" client and my keyboard. So, Musescore with pulseaudio backend doesn't create midi client in alsa? Why?

Portaudio and jack are not what I want for Musescore, starting another sound server for scorewriting??? (by the way, I tried to switch to portaudio, but it didn't work, there is no devices in portaudio settings and "Play" button grayed out, restart didn't help to)
Alsa backend works, at least for me, but I didn't hear about problems with alsa applications running with pulseaudio, pulseaudio catches it and I can even send this alsa stream to any device that pulseaudio uses. So why don't you make alsa backend default in linux? OR implement alsa midi client while running pulseaudio?

If you need a tester with experiments in pulseaudio - tell me what to do, I am ready to help.

P.s. Oh, maybe I should post it in feature request?