i have a 2 monitors and i play minecraft on one, fullscreen, when i try to configuer the mouse settings it takes both my screens and not just one monitor. it could be that it is an convigueration setting or something but its really frustrating. i play on forge 1.20.1 i think latest version of the mod
edit: it also isnt taking the bottom of my screen as the outside boundry

it fixed itself i think, oh wait no they didnt
i had a good setup but as soon as i joined the game it was completly messed up and it broke

There is a key to reset the cursor's origin, by default its the R key but you can change it among other things in the vanilla keybinds menu

You can just place the cursor at the position you want to be the new center, and press R to set it as the new center (it should also work when the cursor is hidden)

the hole thing seems to be at an offset, i have a video but its too big

every time i load the configuration the point of the zero changes so one time its in the middle of my screen the next its all the way on the left

Is your issue solved?

that seems to have fixed it

I will consider this as fixed, if it did not let me know and I will reopen this issue