This might not make sense, but if The Condensce was from Alternia and arrived at Earth, and both of the planets universes are isolated in two frogs, does this mean that Condy broke out of one frog, travelled to the trolls session and entered another frog? Did this happen to Joey and Dammek too?

Yes, there’s inter-Universal travel at play here, although we have no idea how Condy did it yet. It’s possible we’ll learn more about what she did in Hiveswap.