Oh well now I know I'm not alone about this. I've only ever made one comment like a year ago on a game then suddenly it's telling me my accounts flagged.
The automated system might suspect your account to be hacked. Or it just triggered for a combination of other factors.
The filter is getting better in my opinion. At least I see less spam at the places where I used to see a lot. Unfortunately, that also results in a lot of false positives. And there used to be more complain threads about the spam.
The criminals tried a lot of different things. Links to github, patreon, Itch itself, images and whatnot. Posting from new accounts, from slightly aged accounts and from hacked accounts.