I don't remember the slides being plastic. iirc they were metal spring like fingers....but I could be miss remembering.
maybe you've got a screw loose, lol.
Steve...you had one apart lately....let me check the OEM.
Mine in my car are a yellow plastic like material. I bought the repop entire chrome set and it sucks. The lid is actually thinner than the factory lid. I had to space my tighter with thin pin stripe. Tighten up the gap so it’s not seen.