fkndean Delete that item, and create it again, it should be solved then. It's just a load issue.
ShadowArmadyl In my case, Cloudflare was the main issue. I think Flarum is not ready for the system Cloudflare uses yet. My solution was disabling the option that says "DNS and HTTP proxy (CDN)", on my domain, in the DNS section. Then just log in your forum again and the issue should be gone. Just in case, try also clearing Flarum and Composer cache.
I would actually also like to politely ask @jordanjay29 or any developer about it. Is it actually a Flarum issue? or Why is it happening?