I had the same problem with FR 920 XT. The cable was working fine, however (because I could connect my watch to my computer all right). So I wiped the contacts of the watch and of the cable with a cloth, in case there would be some dust or dry sweat, and now it started charging!
On my clip one of the pins wore down to the point that it was no longer making contact with the watch. I bought another one and now charges with no issue.
Thanks for the advice. I did the reset and now it is working