I create a portal token, place it. All works well.

I jump in the portal, I get teleported in to Ratlantis just fine.

However, immediately after, it seems to teleport me somewhere else. Not sure why. Even if I don't move after entering the portal it does it.

Only way to enter ratlantis is via creative mode.

In some cases, me entering the portal will teleport me to the portal on the other end, but as I said instantly teleport me underground and I suffocate.

The server seems to 'lag' while generating the biome for the first time (expected)

The problem persists no matter how many times you enter the portal.

[14:03:11] [Server thread/WARN] [minecraft/ServerPlayNetHandler]: DatsiK96 moved wrongly!
[14:03:11] [Server thread/WARN] [minecraft/MinecraftServer]: Can't keep up! Is the server overloaded? Running 2662ms or 53 ticks behind
[14:03:15] [Server thread/INFO] [minecraft/DedicatedServer]: DatsiK96 suffocated in a wall

Forge 35.1.13
rats-7.0.1-1.16.3.jar
ratlantis-1.0.0-1.16.3.jar

Fixed in 5e55839