kunzisbad

As the title states; I recently set up a modded server using a custom modpack. After some troubleshooting and figuring some things out since I'm not super experienced running servers, the server works just fine. As far as I can tell by running around in creative for 5-10 minutes, every mod is functioning as intended and the server held up just fine to whatever random stuff I did to try to get it or my client to crash. However, on the multiplayer screen when going to join a server, it says that it can't connect to the server. This seems to be a very minor issue and I think I know why it's being caused, that being a mismatched mod list - even though I've triple-checked that all mods required to be on the server are on the server and vice versa. Just making this post to see if anyone else could tell me why this is happening and if it even matters, this is just a small server for some friends and I, but I'd like to resolve it if possible so people can see if anyone's online without having to actually join the server to find out. Thanks for any help you might be able to give me!