Plutonium

I was banned around 1 year ago(summer of 2023) and I’m still salty about it, I was banned twice before for cheating (on a single player game each time) so I decided to be an idiot and play it on offline mode which if I remember correctly said that the anti cheat was off so I decided to use the cheat software then and I got banned for roughly 997 years. Why was I banned during offline mode when it said no anti cheat?