I believe that is a moon roof track guide and wait for it, I studied for just this moment: it’s broken.
Welcome to the F150 broken moon roof track club. The membership is vast.
I’d leave the moonroof closed until they have the replacement parts in stock. MAKE SURE that they don’t give the parts to someone else. This is a very common breakage, so chances are when the tracks come in, there may very well be another F150 waiting for the same parts, while you’re waiting for the service dept. to call you saying ‘hey your parts are in’.
Once they replace the moon roof track/assembly, you can prevent this failure from reoccurring by
1) pop the moonroof to vent position first, always.
2) lower from vent.
3) move panel rearward.
lube the rubber to glass gasket/seal with Ford’s exclusive Krytox grease. expensive, but a little goes a long way and it works.
Open the moonroof regularly, even if you aren’t going to use it.