I discovered a way to get everything working with Garmin Connect Mobile. I'm getting notifications, weather updates, syncs as it should, etc.
All it took was to buy an iPhone.
It's clear Microsoft and the mobile community has turned their backs on Windows 10 Mobile and I just couldn't take it anymore.
It's amazing how many Windows 10 Mobile apps have been updated on iOS. Sad in a way as well.
Good luck everyone. Maybe we'll get lucky and Garmin will give GCM for W10M one last update before closing the book.