Playing 1.20.1 forge, with Ars Nouveau, Elemental, and Creo. Have not done much in the mod yet. A bit turned off that my spell cost is changing on me. When i load into the game i can use my spells a decent amount. But then in a short amount of time, that cost goes 3x-4x.
For example, the simplest spell using Projectile and Harm, when i load into the game, i can fire 7 times before letting it recharge. But this soon changes to only 2 fires before i must recharge. I don't know enough about the mod to know which one would be standard, but i have base mana as far as i know. It's possible the issue is that my mana pool goes down?

I have not determined what causes this, it is possible it happens after dying. Regardless, the only way to fix it has been to log out of the server and rejoin.

This was just fixed today, once the update is approved the fix will be available