On the server i had a mappack and all the maps worked fine, but then i added more maps but they were outside of the mappack. I tried to connect to all of those maps, but it got stuck on the loading screen and just kept changing server name color from grey to black as it does that before it goes to the server, but it was just stuck and didint go to the server. I removed the mappack which i had uploaded, and after that the maps worked. Now i uploaded the mappack to another server and this server just has mappacks and all of the maps on the mappack works fine, but now it gives this same bug on old maps which were on the server before this new mappack.

So how can this be fixed?