Audio tracks without function on Ubuntu-20.04?

[dailybug2]

Issue#1: MusE-3.1 build from GIT refuses to create audio parts on an audio track. There is no way to create a part; neither using the menue entries nor the double click between locators.

Issue#2: A created input track if set to stereo and connected to the jack input (stereo too) only receives signal on the left channel, according to the level meters. This mono sicgnal cannot be recoreded because of issue#1.
I tested this with audacity (audio mode: jack, stereo track) and it works.
Observation: MusE reports on startup that it cannot read the jack version from its API.
Version conflict on 20.04? MusE not adapted to recent JACK API changes?

An here is my yes-list:
- Yes, I connectet both inputs to the audio track. Everything looks perfect!
- Yes, I removed *all* configuration files (MusE, jack, qjackctl) many times to start over from scratch and I do not have a specific ALSA config file.
- Yes, I rebooted.
- Yes, there is no pulseaudio trashing the audio system. Uninstalled!
- Yes, there is no other app running which would do audio.
- Yes, I tested jackd started by MusE and jackd started by qjackctl, with many many different options.

MusE audio is totally screwed up on my PC with no ideas left how to fix this. I spent 3 hours. Ideas, anybody?

Kenrel:
Linux XXXXX 5.4.0-29-generic #33-Ubuntu SMP Wed Apr 29 14:32:27 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

[Tim E. Real]

Issue#1: Only Wave Tracks can create parts. You should be able to manually draw a part on them, or record a new part on them.
Check that the Show Wave Tracks button in the Arranger toolbar is clicked, so that Wave Tracks are being shown at all.

Issue#2: If the Input Track shows that two Jack ports are in fact connected to channel 1 + 2, then it should work.
Note that when an Input Track is switched form stereo to mono, any existing Jack port connection to the right channel
will be lost upon switching to stereo again - you must manually reconnect that right channel Jack port.
Check those connections carefully.

MusE reports on startup that it cannot read the jack version from its API

MusE simply attempts to read the Jack version number using the published API function.
Ever since Jack-2 was created, there has been NO valid version number reported by the function. It always says 0.0.0
Meanwhile Jack-1 reports a valid number.
If something has finally changed in Jack-2, where it is supposed to now report a valid number, well, we sure aren't getting it then,
and the version function must still be broken. Because all we do is dutifully query the function. The rest is up to Jack-2.
When the day comes that the Jack-2 version function is fixed, MusE will be ready for it and the warning message will go away.
The warning message is benign. We simply recognize that the function is not returning a valid number (0.0.0) and
assume it is Jack-2.

[dailybug2]

OK, I was wrong regarding recording. Recording works but can record only the left channel. This was a typical newbie-issue. Sorry for that.

The left-channel-recording-only issue persists, after reinstalling MusE, jackd and the ALSA utilities. No need to say that this is a total killer for MusE / for me. I wonder if others have this problem too. I will create a new thread to get the subject right.