OK so I made my first portal to caveland, and the first time it loaded up everything was fine. But when I tried to come back to the overworld , due the instant transportation of the portals and the fact that it kept spawning me inside my portal, I was stuck in a "portal loop", where it kept transporting between the overworld and back indefinitely, until I closed out my game. Is there a way to fix this or delay when I go in the portal and get transported? Sort of like a nether portal but not that long?

I get the same thing. I'm playing the RAD modpack which includes this mod. portals for other mods work fine. but for this mod, as soon as the destination dimension loads, it thinks the player has entered the portal on that side and immediately start the portal again, switching back/forth between portals. it's impossible to leave either portals, so you're stuck in a loop.