beehater

I was looking for information on in-ground pool ladder bumpers. My liner is in it's third year this year. I noticed where the ladder bumper hits the side wall the print of the liner has been removed in a half circle shape, just on the right side. No actual cuts to the liner the print is being rubbed off. The bumpers I have are/were new three years ago. Is this common? Thank you for any knowledge you may share.