There are a whole lot of things tried in this forum - I think this really has to do with a 2.4 GHz wifi signal. This appears to be the ONLY connection to the internet that "counts." To resolve - I went into my router settings and switched OFF my 5 GHz signal (only leaving my 2.4 GHz signal active) - as soon as I did it started working (To force the connection to wifi I did disable my Cellular data.). I think most other cases suggested were when people got lucky and happened to have been connected over 2.4 GHz (like leaving things connected overnight, etc.) There are certain cases where a dual band router will switch the signal you're on and sometimes you can just get lucky. I do have to admit when I was at work I did multiple hard resets, etc. but nothing worked until I purposefully connected over 2.4 GHz. iPhone 11 - iOS 15.1 Apple watch series 3