Andauernde Neugier

A token that's a copy of Enduring Curiosity won't return to the battlefield when its last ability resolves.

Cat and Glimmer are both creature types. Enduring Curiosity won't have those creature types when its last ability returns it to the battlefield because it won't be a creature.

If a nontoken permanent that's a copy of Enduring Curiosity dies while it's a creature, it will return to the battlefield as an enchantment when its last ability resolves. It won't have any card types other than enchantment.