Yesterday I turned on my 530, created a workout in Garmin Connect on my iPhone, scheduled it on Garmin calendar, and minutes later 530 prompted me to do workout.
Last night new workouts for today/tomorrow were loaded in TrainingPeaks. Just turned on my 530 and those synced immediately (about a minute after main screen appeared on 530).
I’m not seeing any Garmin sync issues with the 6.00 firmware on the 530. I upgraded before Thursday workout, so 3 days in a row the syncing has worked 100%.