Comment 5 for bug 1922543

I uninstalled pipewire (0.3.10-4) and the profiles are always the ones they should at every boot. I tried to install again pipewire and the "changing profiles at every boot" appeared again. So, it's the source of the issue.

I don't know if it was installed by the base Ubuntu or KDE/Kubuntu, or any program i tested (i don't have any of its inverse dependencies installed) so i will keep it uninstalled, and if is installed in the new (K)Ubuntu version (hirsute) it should be a fixed version (It will install >0.3.24-3, and in the issue you linked it seems it fixed in 0.3.19-3).

Thanks to put me in the right path.