you could try out the following steps:
In the M2P interface, enter the „Raspberry Settings“ menu and check whether your soundcard is set correctly. If not, change it, reboot and try again. The sound card should also be selected in „Audioplayer“ -> Squeezelite -> Advanced settings.
Make sure to stop KODI and Shairport before starting a Squeezelite Player. If it makes sense for your setup, disable „Autostart“ for KODI and Shairport to prevent this issue in the first place.
Maximilian from Max2Play