Watch series 3 iPhone sync connection issues

Hello.

I’ve been having some issues for a while with syncing my watch series 3 with my iPhone 11 pro. I’ve been doing exercise always with my watch on and it doesn’t sync the info to the iPhone Fitness app.

I’ve done everything that people say on the Internet, turn on/off plane mode, reset data, unpair, restart iPhone/watch, whatever.

It has worked some times but most of the times, it doesn’t.

I’ve been a big fan of Apple for a while but this is kinda becoming a bad experience that I wouldn’t thought I’d had with Apple products. I mean, the detail in all the products is amazing but how come there’s not a “Sync” option or button to this kind of issues? This kind of things shouldn’t even happen but still, there should be an easier turn around to this without having to do A to Z things and in the end it doesn’t resolve the question or worse, to buy a new product which is not cheap at all.