Question Debris from Dometic AC unit

[JBright11]

Packing up the coach for a Monday take off on a short trip to Grand Lake OK.
Plugged in at home to 50 amp service as normal, AC set to 80F. Heard an odd sound coming from the rear AC unit, sounded like something "flapping".
As I was climbing the ladder up to the roof a piece of something came shooting out thru one of the vents in the cover. Looks like a piece of masking tape to me.
Opened the cover and inspected and found one additional piece inside the squirrel cage. Nothing else visible, and I cannot locate anywhere inside that these pieces came from.
Don't really want to start unbolting things or remove the unit from the roof, but I can't find anything that looks out of place or missing.
Any idea where this could be coming from? Unit runs fine; coach is cool.

 

[Holdmybeer]

Foil tape is often used to seal the plenum. Masking tape, not so much. Perhaps it somehow made it’s way into the housing via the vent.

 

[Boat Bum]

Perhaps a label that was affixed inside the cage that just rotted off.

 

[JBright11]

I thought perhaps a label as well, but there is zero print visible, and I can't see anywhere that looks like it was originally attached.

Foil tape I would understand, not that it should be coming lose, but I understand that it is used to seal AC units and ducting.

Likely not a big deal as everything is working fine, just odd.