If you're below 8st/5ft3", could you please measure your bath and let me know the overall length (including lip), also if it's a P shaped bath. Can you easily stay put when you're in it?
I've only used our present one about five times in ten years as I just slip into it, unless I hold my legs tightly to the sides or hold side with my hands. Never had this problem in homes before. I suspect it's down to volume of water verses my weight (ie long and a P shape needs more water) or the length as my feet can't reach to the end. We're having new bathroom, so trying to work out the problem.