I had the same issue, but today my mobile (Mi note 8 pro) updated to android 10 and suddenly i started receiving whatsapp call notification on my galaxy watch R800, i can answe it as well. I guess the problem was with my mobile after all.
Hi purchased galaxy watch yesterday and paired it with Samsung Galaxy S9 plus. The WhatsApp call feature was working fine and the watch was even displaying the name of the person who was calling. However, next day (today) the watch is not showing the WhatsApp call notification. No software got installed over phone or watch overnight.
If you guys know of any setting that needs to be changed, kindly advice.
Try changing the notification settings in the wearable app. Toggling between on and off for all the notifications you want. If nothing works try resetting the watch and pair again.
Thanks for the reply, I have already tried toggling the notification settings in wearable app. It didnt work so i tried resetting the watch and paired it again. Still the issue didnt get resolved.
Was excited to see this feature but it went away next day :(