Apple Watch Ultra Pausing Workout by itself

Hello guys!

Got an apple watch ultra and I'm using it playing tennis, first time it paused the workout by itself, then in the second time I locked the device (water lock), so it wouldn't take any action...it did not work and ir paused again :(.

Is it happening to anyone, on any kind of workouts?

I know there is a menu to turn off the auto pause, but locking it should prevent it from pausing, right?

I like the auto pause when I am walking, jogging, etc.

My series 2 and 5 never paused itself, unless I was like jogging and stopped for a while.