Nothing. My other account was only for lurking and I didn’t post anything; no comments, no posts, nothing.

I only post / comment on my main, but that’s now no longer possible lol.

It’s a sound theory, however I am not banned from any subreddit as far as I’m aware of, so ban evasion can’t have been the reason.

Although, as I mentioned in another comment, I have another account, but that’s mainly used for my nsfw stuff.