Syncing workouts

If this were due to a problem with Connect Mobile for Android I would have expected a lot more complaints, but just to be sure and to isolate the issue: no one else unable to send workouts to their device from the mobile app?

I can't send a training program either. It used to work.
It works if I do it one by one.

It works if I do it one by one.

Can you tell me what you mean by 'one by one'? I always send every workout separately and that does not work anymore, but maybe you mean something else?

Sending courses is now also problematic, the app mostly crashes when I try to send one, but if I keep trying over and over it works eventually (1 out of 10 tries successful).

For the workouts, I'm now writing my own workout creator so I can transfer workouts via USB, but I would much rather go running than programming :(

Sorry, I wrote a quick answer yesterday but it got lost in the interweb.
I used to upload training plan to my watch (actually a F5, previously a F3) for a duration of 5 to 10 weeks, up to 5 sessions a week. And it worked fine, last time was in may.
After some time off training and an injury, I'm back in training.
I wanted to upload a training plan until Xmas, but thru Garmin Connect, it always says there is an issue, it doesnt work either thru Garmin Express on a pc.
When I want to upload a session at a time, it works erratically : sometimes yes, most of the time no. So I must give it a few tries before the workout gets on the watch.

Thanks for explaining! Just wasted my lunch break on trying to figure out from the device sync audit logs and logcat what goes wrong, but nothing. "Browsed: no items to process". While with a course, it logs the browsing and downloading perfectly fine. Giving up on this app functionality, back to programming.