You are not alone.

eBay’s AI system for policy breaches is horrendous. So many listings are being flagged incorrectly, and there is nothing you can do about it. Equally, there are huge amounts of listings that breach policies, even break the law, but not only does the AI not pick them up, reporting them results in it saying there is nothing wrong.

Why some and not others? - nobody seems to know.

And that’s when the policy breach is clear.

Given that "Police-related items policy" simply specifies "military items" cannot be listed, that is hugely vague and all-encompassing in itself. So at any time you could find that your Royal Navy / other military items are all removed because of this policy.

It's anyone's guess exactly how and when eBay would enforce this.

You just have to put up with it / try and work with it, if you want to sell on here.