Mine did it. Fixed yesterday...
Jack up car on the side it pops out and place on axle stand.
Wheel off, arch liner off - 4x plugs around the inner arch and 2 torx's under the front bumper.
10mm bolt holds the bumper to the wing (right at the edge nearest the wheel). You can see this just with the arch liner in place but with it removed you can get full access to it. Remove the bolt.
Pull at the bumper and it will come away from the wing.
Now you can see the clip, on the bumper it's a hole, the wing has the lip. I used a heat gun (carefully) from the inside of the bumper (so didn't melt the paint) to heat around the hole in the bumper. Once hot i bent it back up as it'd worn down.
Under the wing right below the problem clip there's a small ledge that the bumper kind of sits on. I wrapped a few layers of insulation tape around it to make it a couple of mm thicker so the bumper sits slightly higher and closer to the wing.
Clip everything back into place.
Do bolts up etc. It's going nowhere now!