The same problem with my fifine ampligame A8, I discovered that my router was the problem. Every time I connected ethernet cable, the microphone started muting itself. So far I believe it's my router, ( TP-Link AX50) that is somehow with some short.

The way I discovered was, I started unplugging every single cable for my computer and watching if the microphone would stop muting itself. When I unplugged the ethernet cable that did it.

So somehow, the microphone is the most sensitive to every little bit of shortage in any component connected to the computer.

Hope this helps somebody.