Yeah, monetizing fanfictions is illegal and is specifically forbidden in the site ToS and content guidelines. Writing fanfictions for free is a grey area, but once you take money for it, you break copyright laws. Recently the site started to take more hardline approach in enforcing the rules, to protect itself from legal action, as you found out.Yes I think that's why. I didn't put it in my chapters but my description. I have deleted it already. I've seen some fanfics also insert their patreon in their description so I emulated them.