I just found a fix to my versa 3 issues, I hope it helps you too. I’m a runner, and my versa kept shutting off on route, I kept having to restart, and I was losing my data. I never had an issue with my old Fitbit with the side button. I know this sounds crazy, but I loosened the strap and the problem went away. The issue with the versa 3 is that the entire watch is a button: if the strap is too tight, moving your wrist or arm clicks the button. And shuts off your exercise program. I could see this being your problem with weights too, or with any exercise that involves the arm or wrist. Although the band feels a bit loose, it is still recording all my data. . I hope this helps.
