Stevie
In the 10 years I have had ny 92 daily driver it happened to me a couple of times. I think what happens is that the front spoiler flexes and the cover then pops out.
After it happened twice, I used a very small amount of clear silicone glue around it when I replaced it and it hasn't come off in 5 years or so. If I was smarter, I would have done that after the first time!
Good Luck