So I have studied the problem on a private server I created. I have found out when it can't read that you're in the skywars lobby it sends you back to the original lobby, it does this because the server assumes your flying because of the fact that you have this property set to "allow-flight=false" in the skywars lobby of server properties. If you change that to true, it will allow players to fly within the lobby but if you don't want people to exploit the map, just add barriers around where you don't want the players to access. Now if you think that the skywars games will be infected with the same cause your wrong about that. The skywars plugin has its own properties and disables flight in games. If you think it might increase the likely hood of hackers, just add an anti-cheat to the server or just get a stronger plugin.

Kind regards ~ ItzAnimal

 

Going on with the Idea of barriers I would be glad to help you, if required.

 

I agree with what animal has said he is correct barriers and an anti cheat or stronger plugin would work a lot better
-Pug_Lover_932
Savages.

 

This isn't just a problem on Skywars it has happened to me a few times on different servers.

Although I do not see a point in having people just fly around, I guess if there is a way to make it so that people can't fly but it not kick you from the lobby, I support.

 

An Idea could be they have a plugin that allows you to fly until you press a key on your keyboard.