Step 1: get to a safe area to quit and save
Step 2: hold a wand (or item) WITH NO TRIGGER SPELLS <!> THIS IS IMPORTANT <!>
Step 2: press escape key and then open the mods section
Step 3: disable Spell Lab then click save & quit
Step 4: reopen Noita and enter the Mods section
Step 5: enable Spell Lab and click Continue

your GUI is now fixed

HOW TO AVOID BREAKING IT:
from what ive seen whenever you have open a special menu (almost anything but the spell picker) and you are holding a wand with a trigger type spell (timer, trigger, etc) it will bug out the UI and shift it offscreen to the bottom right.