SCOTTC34

I am having an issue with the timing belt, car has 220 thousand on it and I have replaced the timing belt a few times recently. I am having a problem with the belt wanting to ride off the cam pulley, mainly on the side of where the auto tensioner is. I first had put aftermarket parts on it so
I decided to change the water pump to oem, that has'nt stopped it.I have thought about changing the tensioner to
oem but before I did that I wanted to see if anyone else had
run into this problem, the outer edge is rubbing against something. Thanks for any help!! Scott