Hi. I now have the new Samsung watch 5. All is good apart from I cant make or receive calls without having my phone on me (so when I leave the house I have to take my phone with me. A bit pointless!) I have a galaxy S21 plus 5G and I have Ver 12. So can't think this would be a reason for it not to work. I've contacted the mobile provider (o2) and they've checked everything and say the settings are OK and samsung say the same (but they will replace my watch but don't think that's the issue as its brand new)
I have a solution that worked for me, but the T-Mobile Technical Support Agent says the fix may be different for different phone setups. I just returned from T-Mobile to get a solution to the problem of not being able to call away from my phone. I have a Note 20 Ultra 5G. I first spent time with a level one T Mobile customer service agent to confirm all the parameters of the watch were good. Then got passed to a higher tech level of support. The T-Mobile Tech Support agent out of Albuquerque said they just learned how to fix this problem by accident. According to him, the WiFi on the watch interfers with the LTE signal. We turned off the bluetooth on my phone and turned off the WiFI on the Watch 5 and attempted a phone call which was successful. He said the Wifi on the watch is really not that necessary and eats up the battery. But now my Watch 5 can make and receive calls away from my phone. There is nothing about this in the User Manual for the Galaxy Watch5. But I was also told by the T-Mobile rep, that sometimes, the watch is not properly set up from the beginining. My husband has the same problem with being able to use the Watch5 as a phone. But the same fix that worked for me did not resolve the problem with him. He has a Galaxy Note 20, so I will call tech support again to try and get his watch working. Hope this helps some people.
One more thing. I hope Samsung addresses this problem. I love the Watch5 and the reason I got it was for the phone capability. The T-Mobile Tech Support says he gets about 5 - 6 calls a day about this problem.