Try the work around of making sure the phone isn't on silent and try switching them off and back on again, see if that does anything. My Husband went into the Samsung shop yesterday in Cardiff And they wanted to know how I managed to do it because they had customers in with the same problem and didn't know how to overcome it, it's crazy! Hope it works soon for you, let me know.
Still nothing on mine. Have down loaded chat hub and what's history so at least I get some kind of WhatsApp notifications but it's not how it's supposed to be. Glad you got yours working though.
I think it is fair for each user to tell us his mobilephone type. Maybe we can tell if galaxy watch performs differently under different phones.
Mine is LG G6, and galaxy watch works perfectly only if the phone is on vibration mode.
I could not get it to work. Samsung don't want to know as it's a 3rd party app and WhatsApp won't help either so I got fed up and have sent it back. WhatsApp is my main platform so it was no good to me not working. Someone on here has got it going though but I'm not sure it will work for everyone. It definatley didn't for me but good luck !!