The problem is your wording was poor at best. You said “ I'm a UK resident, and might not be understanding things correctly. *We don't do book banning or excluding over here.*”.

This makes it sound as though NO book is EVER banned or excluded. Which is blatantly false.[0]

If you had meant “we don't have any centralised list of books that can't be in a public or school library”, then you should have said that. Not make a false general statement. Though I’d be pleasantly surprised to hear that there are laws in place to prevent local/central government bans, considering the UK’s history of such things. Wikipedia doesn’t list such a law, although it does list that the last banned book was unbanned by your government in 1992, and that none have been added since.

[0] - https://www.theguardian.com/books/2023/apr/20/third-of-uk-li...