Watch face resetting

I have the same issue... I think it happens when it comes in contact with either your hand or clothing as it brushes over the face, and it slides it to the next face. Unless there is a different answer. I think to eliminate this you edit your watch face to only have the desired option in the selection area. Which can be edited in the watch app on the phone. If this is wrong maybe someone can give us another, easier, option.

Remove all watch faces except the one you're using.