I’m getting the same results. I downloaded a sketch and at the end, ttyACM0 disappeared. I have second Wio Terminal and the same thing happened. I have not been able to get it back.
I do the quick double reset and I get the Arduino drive back (Linux Ubuntu 20.04 OS). So I don’t think it is totally bricked.
I tried the factory reset - Hold button 1 and reset procedure.
After compiling, it says “Sketch uses 278032 bytes (54%) of program storage space. Maximum is 507904 bytes.” So I don’t think it should have overwritten anything.
Thoughts?