Linux client: No stereo audio playback but stereo audio sent to other participants

[appalloosa-cob]

Zoom 6.6.0 and earlier 6.x versions suddenly stopped playing back stereo audio on Linux. I have original sound for musicians enabled and stereo audio selected. It does not matter if high fidelity mode or echo cancellation are enabled. Other people in the meeting get stereo audio from me, but I am only getting mono back. The other side has stereo audio enabled and other meeting participants can hear them in stereo quality.

The Linux audio system seems to work fine: When connect a DAW like Reaper instead of Zoom to the same audio ports, stereo audio is recorded and sent back.

I am using Ubuntu Studio 24.04 with the default Pipewire sound system.