Same problem. I have tried unpairing, repairing, deleting the app, logging out, etc. Nothing is working. I haven't tried more drastic measures such as resetting the device yet. I don't think things should come to that and from what i've read it doesn't see, all that effective.
Also since the 3.6 update, syncing is as slow as a snail. It can take upwards to 5 minutes to sync (when it was working). I hate to say it but garmin software is horrible.
Slightly relieved it's not just me, since the 3.6 update BT connection is unstable sync is very slow and has taken at least two attempts every time. Wish I'd left it how it came from the factory, it was working perfectly.