So a few days ago I started a new CC save on top of my main one, both of them are running at the same time on different tabs of my browser (I am backing them up separately)
I just now activated the grimoire for my new save, and when I cast the first spell my all time spell cast counter on this new save instantly became the same as on my main save (182). I also got the "cast 9 spells" and "cast 99 spells" achievements on this new save instantly.
Mana bar on my main save:
Mana bar on my new save, right after activating the grimoire and casting one spell:
Backing up my save and loading it back again didn't change anything.
This is also the very first time I've encountered a conflicting number between two different CC tabs on the same browser.
I would open a new fresh save, give myself a sugar lump, and cast a spell to see if the spell counter would conflict again but I don't actually know the command for giving myself a sugar lump