Prag, as others have said, watches don't seem to do a good job of measuring BP. I bought an inexpensive Xiaomi to track my activity and heart rate, it is fine for that. It uses an app to link to my Android phone and I can see the data from the past week or month. Also lots of different face designs to download. When I looked I couldn't find a watch recommended for BP but that isn't one of my problems. I have others, but my BP is a steady 110 over 65 so I didn't look too hard at that when I wanted a watch. There is a Xiaomi watch now that claims to measure blood glucose and BP, about a thousand Baht on Lazada. That might be worth a look.
I have an American friend who has been a serious runner most of his life, he still runs daily and has a BP usually 160+. It makes no sense at all.