Hello. We are having this problem on the server.
We have a server that we play with friends, and out of nowhere this list appeared on the right side that makes the game's FPS 6. It crashes a lot.
It gives an error in kubejs but we don't know how to solve it. Could you help us?

Open FTB Quests book, disable Auto-pin on Bottom Right corner
I get 1-2 fps with that enabled.

Don't know how you are triggering this to be enabled.