I am 7 weeks into a 16 week Garmin training plan. For most of that time I've had no issue at all (apart from the lack of power-matching between my Vector 3 pedals and my trainer). I've made minor changes to various workouts during that time and everything was syncing up nicely.
As of this week, though, changes to a workout were not showing up in the plan on the 830, despite correctly showing on the Garmin Connect web and the mobile app. Editing the workout on either of those two platforms sees them sync with each other but not the Edge. Instead, customised workouts are being pushed to the Edge as standalone workouts, leaving the plan unchanged, but showing up under the Workouts folder.
The only fix I've found so far is to plug the Edge into a computer, delete the .fit files in Garmin > Workouts > Schedule, and then sync. This works once, but any other edit to a workout subsequently fails to sync, requiring deleting the files again and re-syncing.
I'm unsure if this started happening only after the latest firmware update, as I don't edit the workouts every week.