I haven’t spent much time with the Charge 3 because I have had my hands full with the Polar Vantage V.
Did, however, pair it to an Android phone. Pairing worked fine. Then discovered that I can’t SYNC it!
So, removed it from the phone and paired it AGAIN. Still can’t synch.
A little bird has told me that this might be a KNOWN issue — at Fitbit!
I am a bit put out. I will, of course, keep you posted.