Wasn't able to find it answered elsewhere- this happens to both the passenger and driver sides of my car. Carpet is not secured at the side closest to the door, and separates out away from the plastic sill cover. Can be tucked back in, but simply pulls right back out over time with foot pressure and usage in the footwell . This occurs regardless of the type of mats used for driver and passenger.

Seems to be a design issue affecting multiple iterations of the body style.

For those who have also come across this, what was your fix? Thanks

That's usually the result of minor shrinkage/deformation of the carpet and settling of the foam spacers underneath it over time. My solution is usually to pull up the sill trim and loosen the edge of the carpet, then add either a foam noodle at the outside edge of the floor pan or a foam mat across the whole width to prop the carpet up slightly. It also often helps to pull the carpet toward the front and safety-pin it to the firewall undercarpet, preventing it from creeping rearward and creating slack.