you mean players will be displayed in tab according to their world?
Like if three are playing and two are in 1 world then only those two get displayed in tab?
if it's your server go to https://minehut.com if you haven't logged in then login, after that a dashboard opens, there you'll find a box named "server commands" in there type /pardon (your ingame name) and done! you can play.
List down the plugins, and are you sure you have the dependencies needed for a specific plugin to work.
You can find a list of plugins needed for some other plugin to work in the panel in the plugins section.