Can't use IMG bbcode in signature.....page refreshes and turns off dark mode.

Whenever I try to use an image as a signature in the signature section using the [img][/img] tags.....it refreshes the page and turns off dark mode but doesn't parse the BBcode or image......there should also maybe be an ability to upload/attach an image as a signature, maybe as a groups permission?

here is a pic:

Edit: Okay so after futher investigation, it does work, just that there's no signature preview. This might be a feature to add in the future.....but the dark mode turning off upon signature editing still needs to be fixed.