Equilibrium bug

[Petrichor]

For some reason, the spell Equilibrium (from the mages guild questline) does nothing when at full magicka.
I ran a bunch of little tests to see if this was because of any of my mods (it wasnt) or perks (still no). When i used console to try to replicate the effect on a new (but statistically identical) character, the same issue happened. When i tried it on a character that wasnt a High Elf, i never encountered the bug. As if the game wasn't anti-elf enough, now the game engine hates me too.
Essentially, it drains ~0.2 magicka per second when im at full magicka, but if i cast another spell before casting it, it works as intended.