Why can't websites that search for communities find mine but it can find someone else's that has the exact same name on another instance?

So I made a community on lemmy.ml. There is another community with the exact same name as mine on lemmy.world

When I use a website to search communities across instances like lemmyverse.net or browse.feddit.de it won't find my community but it will find the one someone else made on lemmy.world

If I search for other communities I made on lemmy.ml on those sites it displays the results fine. I've also went to lemmy.world and searched for my community with the URL and the !@lemmy.ml and still no luck

Can someone please explain this to me?