Yes, Sounds like shedding to me as well. Perfectly normal.
You may observe them wipe their faces and wipe one back leg with another.
Heather's photo is perfect to show the position they will be in when they start.
You will see them suck in their abdominal area, which is to loosen the skin.
They tilt their heads back and open their mouth very wide when they start to get the skin loose around the mouth.
A red eyed tree frog typically sheds as soon as the lights go out, as you have mentioned.

If they were kept in an enclosure without the improper humidity, they may not have been able to shed easily.

Enjoy your frogs !
Lynn