New Edge MTB not connecting to Garmin Express on MacOs Sequoia

I have several Edge units, which all work fine with Garmin Express.

However, GE won't recognized my brand new Edge MTB and as a consequence, freezes GE altogether.  Only solution: restart the computer.

Since, everything works fine with my other Garmin devices, the problem must be with the MTB unit (BTW it enters into mass storage mode).  I then performed a full reset but nothing changed.

Any hints/explanation?


Thanks in advance.

PS:  Permisssions are all set correctly in MacOS Sequoia.