No sound with jack2 and stuck in 48000 Hz in Debian 11

[lucmp]

I have a brand new installation of Debian 11. Sound worked fine with ALSA after the install.
Then I installed jack2 and Cadence. Cadence brought along its own companion applications.
Now I have no sound. Audacious for example can't play anymore (multiple errors).
Jackd is not started automatically at startup. It starts when I launch Cadence. But Cadence is stuck in 48000 Hz. I changed it to 44100 on every configuration tab (ALSA, Dummy, Loopback, Net, NetOne), but I restart jackd and Cadence still shows 48000.
Audacious complains about it and tells me I have to enable a conversion effect plugin.
I enable it and I get sound! But tracks play veeeeeryyyyyy slooooooowlyyyyyyy.
Either way, I don't want 48000. I want 44100.

I have it all working in Debian 9, but I don't know why it works there. I just remember that configuring sound with jack2 was very difficult. It is one of the reasons I still use Debian 9. I'm just experimenting with 11 to see what works and what doesn't.

Can someone please tell me how to make jack2 run in 44100 Hz and how to get sound out of it?