The old Google Chromecast Audio device was a WiFi only device like WiiM Mini but it was possible to use an adapter which provided both 5Vdc power AND ethernet into the microUSB port.
Google sold such an adapter and it worked really well for me:
Is this possible for WiiM Mini to support something like this? It would need to be USB-C of course.
This would eliminate lots of WiFi issues.
This was another one that worked with old Chromecast Audio device (microUSB):
The microUSB carried both power and ethernet data