This is the third time this happens.
For the last 3 updates of Garmin Express on MacOS, the app couldn't start nor sync, even after Force close and full OS restart.
This is beginning to really annoy me. Place the app in the Mac App Store and rebuild it to work properly. THIS IS UNBEARABLE
For now I'm uninstalling the app entirely from my Mac computer. Try fetching the updates through my Android device
Kind regards
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Uri