Can't delete new mailbox
I accidentally created a New Mailbox under the wrong location (an existing Gmail account). I attempted to delete it by going to Mail > Edit > Selecting that new mailbox > Delete Mailbox. However it did not fully delete it and now it's showing at the top of my Mail, grayed out and unable to open or edit. The only thing it will let me do is move it up and down, but I want to remove it completely. It has a folder icon next to it. Any advice?
iPhone 13 Pro, iOS 15