What reason are you talking about?

The only message that I can find which might qualify is, *“Due to repeated Page violations, you can’t post to any Pages eligible for monetization.”

That doesn't explain what the violations might have been. And in the dashboard where they were supposed to see said violations, no pages were marked as having any violations.

Which boils down to, "Due to repeated violations that we won't tell you about..."

Yeah, in their position I wouldn't consider that an explanation either.

They explicitly said they will not provide any reasons, for "security reasons".