I have never had a need for covers to keep my sensors in place.
I find the biggest issue is finding a flat area of my arm that does not bend.
If you are finding that you are more likely to catch your sensor, then it is more to do with awareness (if it only goes on your right arm for a couple of days, you may be less use to it).
If you are finding it starts to peel off, it is more likely to be that the place you use on your right arm is unsuitable,
If you are right handed, you may flex your right arm more often and it may be more muscley making it harder to find an equivalent flat position to the one you use on the left.