Hi, unsure if they s will help you but my father recently had the same issue. Both his wrist are tattoo' and certain functions did not work. He applied the clear part of a waterproof plaster over his tattoo, where the watch sits, and everything now works. It may be due to his tattoo's being fairly old but it worked all the same. Without the clear plaster these features stop working again.
Hopefully it's not a fluke and it may work for others too, Rachel.