Try to replace PipeWire on Puilseaudio, as in FAQ of NoMachine.
For CentOs 8 by commands:
dnf remove pipewire
dnf install alsa-plugins-pulseaudio
systemctl –global enable pulseaudio.service
/usr/NX/scripts/setup/nxnode –audiosetup
Do not help.
No sound on client
No UDP packages (excl main port) from server, then try to check sound play on server.
Please help.