I looked up photos of past classes and compared them to this current class.  The current crop appears to be very much not Green Tree frogs.  From what I can tell for the older members (now all froglets) they have matching colors/markings/size so I'm pretty sure they're all the same species.  While some of them have gotten on their rocks, they haven't so far been climbing on the container walls.  The first photo is a froglet from a previous class in 2018. The second is from the current class(The Lone Ranger.)

Yup they're different for sure. Now I just have to find out what species they are.