I have the same problem, and I know it's not a bad connection, I know this because Im able to join other servers halfway across the world. It's not just my computer, it's my friends as well. I was able to connect to it before, but right after I installed some plugins (skywars via spigot/bukkit) it kept saying timed out. I have tried the following but have failed.
Using DynIP
Flushing DNS cache
Changing DNS Server
Uninstalling/Reinstalling MineCraft
Restarting my computer
Reinstalling Server Plugins
Computer Specs:
MacBook Air 2017
Thats about it
Lol