I'm running Mac OS 12.5 Monterey and my computer (USB C with dongle for USB A access) can't see the 955 v11.12 at all.
The watch doesn't appear in Finder or Disk Utility.
Garmin Express can't find the watch.
Commander One doesn't see it with preferences set to show MTP.
Android File Transfer doesn't see the watch or just crashes.
I tried a couple of months ago with MacOS 12.4 and 955 v10.xx and there was some intermittent connectivity with a lot of crashes with GE but now nothing.
The above suggests to me that the problem might be a Garmin implementation of MTP issue.
Any suggestions welcome before I return it?