Both of my front corners look that way and wont stay in place when pushed back into place.
My drivers side rear is similar. The corner wont stay snapped. I even took the rear cover off to see what was keeping it from going back together.
Two of the corners have been gently bumped, its a truck with 4wheel drive, so I know that has something to do with it too. Seems like when I push on the right area they stay clipped, otherwise they keep coming loose.
I think heating the correct area would help reform them. I gather that from when I push in the proper place they stay put.