Apple watch not syncing with Health app - Apple, hello???

My apple watch (series 3) and iPhone XR do not communicate anymore, since a long time now. Both software up to date. Data exchange is spotty at best but does not work most of the times: in essence comes down to health app not syncing with the watch and, as a consequence the activity ring and all the related apps (like food and fitness tracking ones) have no data to work.

Also, in Health app under devices, there is a list of old watches and the 'current one' shows 'no data'.

All the above is not new and there are many posts. I do not mean to just repeat but maybe Apple's people read this stuff. Come on fix this!!!!

Tried everything under the sun, including the pointless fix that Apple spits out, like restart the phone etc...completely erased both phone and watched multiple times (watch started as new and not from back up)..nothing fixes it.

The only hypothesis that remains is that the iphone backup is transmitting a firmware error and carrying in forward.

Is this a not so subtle way for Apple to push people to purchase the more recent watch series?