Garmin Express shows the activity as uploading and able to be viewed but the activity does not appear in Garmin Connect. I have tried a manual upload in Classic which has also been unsuccessful.
Since switching to Garmin Express and Garmin Connect Modern I have had a run of issues which I did not experience with the old Ant Agent and Classic Garmin Connect.
I understand the need to try to improve and modernize your platform but to achieve this while maintaining reliability and a user friendly environment you need to ensure that before you go to market with such changes you have these issue's sorted first. Or at least respond when issue's are brought to your attention as I am yet to receive any correspondence from messages I have sent to your support.