Are you using a ceramic to heat up the Viv / rub ??
They're great from a heating standpoint buy in my experience they're a nightmare from a humidity angle .
I cope by simply spraying the Viv well , a few times daily when the snake is in shed and this seems to guarantee good sheds.
For this retained stubborn skin maybe just keep spraying daily and it will come off naturally especially if there's some branches in there .
Sent from my iPad using Tapatalk Pro