I too exchanged the watches and on my third...was told by Apple it’s clearly not the watch..it’s the software. Which..yeah. Makes sense. So fix it please.
They also did tell me that people need to tell them about the issue so that they’re aware of it. Most people just go on the forums but don’t actually contact Apple about it. I don’t know if that’s true but if it is..yes, please contact Apple and tell them what’s wrong.
As for turning of wrist detection like others have mentioned..yes , that would work simply bc the screen wouldn’t dim, it would always be completely on which burns battery like crazy and worse, disables a lot of features that make the 6 series the 6 series so what’s the point of doing that? It should function the way it’s advertised to function.