That's a stuck shed, I would do a humid soak so you can remove it.
Sterilte tub with lid
A hand towel or towel in the bottom of tub
Add 88 to 90 degree water until the towel is soaked and is sitting in water.
Add snake for a 30 minute soak.
Replenish with more warm water and soak for another 30 minutes.
The shed should just about be off or slide right off with a little assistance.
Thank you for the conformation on the stuck shed. I suspected that's what it was but I wasn't sure if there was a difference between "retained" & "stuck". I am about to start the soak process you suggested. Thank you for the advice & tip!