Your distro may have upgraded itself within the past year or so and suddenly some audio stuff does not work as expected.
Pipewire has entered the arena.
Good old Jack is still available but not actually talking to any hardware; it is some kind of compatibility layer. QJackCtl still works, I could even find the old “connections” interface deep in the Misc
tab of the settings. It's actually now better because every device shows up magically; and no need to create “aggregate” devices with the obscure ALSA configuration language.
I end-up needing the following commands quite often (I'm still using Comk):
The default sampling rate is 48 000 Hz which is indeed recommended for most work but I have a bunch of Ardour sessions in 44.1 kHz that I need to reuse often.
pw-metadata -n settings 0 clock.force-rate 44100
to put it back in 48k:
pw-metadata -n settings 0 clock.force-rate 48000
I also encountered that the default “quantum” of 1024 bytes was too large for recording.
pw-metadata -n settings 0 clock.force-quantum 256
That's it, have fun:
pw-metadata -n settings