Don't know if anyone else is having this issue in 2023 but I am..... Tried clearing data etc. Just white screen of death...
edit. this was a weird fix but i did it, install web video cast (i know weird right) https://play.google.com/store/apps/details?id=com.instantbits.cast.webvideo
set that as your default browser
dont set up samsung account at initial setup of watch.
click watch setting (on your phone wear app)
click samsung account
browser wil laucnch
once you sign in then you might get an error saying unable to launch app or something with an OPEN in red press that
you watch will then sign in
the login may come up again i just closed it and ti was fine
