rear bumper - splash guard issue

Hi!

So this afternoon I finally had a chance to install the Splash Guards from Acura.
The front two went on problem free. The back two....different conversation.

This car is pre-owned.
Bottom line: the drivers side rear wheel well is closer in clearance (bumper to tire) than the passenger side. The drivers side bumper also curls up into the trunk area more than the passenger side design.

Does the rear bumper over 5 years change like this? Or do I perhaps have a previous repaired bumper which was not totally done right?

How do i repair? Im assuming a body shop. If its worth it.

THanks!!