PS4 disc drive only takes discs in so far

What is this mystery piece I found inside a PS4's optical drive?

this should address where the mystery piece goes, as far as the disc drive still being sluggish and not fully taking discs in here’s my own experience:

I just had this issue on a PS4 Slim, turned out to be dirt jamming up the grooves in the disc roller gears, it was causing the rollers to be sluggish and skip a little but ultimately didn’t have the torque to fully pull the disc in or eject it once forced in, this would also prevent the disc from settling all the way in so that the drive could properly read it. Once I cleaned out the gear connected to the rollers and carefully used a small jewelers flathead screwdriver and a nylon brush to clean the other two gears it works like new. Hope this helps others with this issue.