The "cursed effect" is not always removed from the twiligh forest progression-restricted areas once you unlock them.

[DeuxVis]

Happening in the smashphyro-modpack official server.

For instance once I killed the hydra the "black swinging ropes" graphical effect was removed from the dark forest, but not the blindness effect.

Might be worth trying to upgrade the twilight forest mod to the lastest release maybe ?

They already have an open related issue in twilight forest github : TeamTwilight/twilightforest#440

Thanks for your attention.

[DeuxVis]

Did a little bit of homework on this one.

First, I forgot to mention that the bug was not immediate : at first, straight after killing the litch I was able to go into the swamp and hunt the minoshroom without being hit by the hunger effect. Now if i get back in the swamp the hunger kicks back - but not the black dots snow-like graphic which was going along with it.

I tried and cannot reproduce it in single player test world. I'll have to try and set up a MP server next, not sure if I will be able soon.