If the lights are new, the fit is an aftermarket flaw with poor material. TRF claims theirs fit now after some problems, but I do not know. I actually cleaned up some old rubber sockets I had, and I got some old one on line and cleaned them. I finally got a complete new set to go together off the car and let that sit and stretch; it is still stretching. The socket was very tight with the rim and light in the housing. Back in the day the rubber was different.
steve