At the CIQ summit the Backbeat Fit 3100 was part of the attendee welcome packet. They paired right up to the F5+ and have been working fine. I just paired them to my VA3M and played some music. It is working fine. Not sure why the BBF2100 is having problems with your watch.
Have you installed the latest BB app on you phone and updated the FW? That was the first thing I did with my headset. The 2100 and 3100 use the same app on the phone to update FW and it was the first thing I was prompted to do once I installed the phone app.