Forge version:
Twilight Forest version: twilightforest-1.12.2-3.3.202-universal

Steps to reproduce:
See here my bugreport on modern skyblock 2
https://minecraft.curseforge.com/projects/modern-skyblock-2/issues/303

Are you on a server?

Yeah this seems to happen when Sponge is on the server, haven't had the time to look into it yet.

yeah it is on the a server and yes on sponge >.<

im sorry for the late answer

Open config/sponge/global.conf and set the max-bounding-box-size to 6000 or higher, or 0.

Sponge's default maximum bounding box is too low for the Hydra.

It works ty x3