I am not able to play on the servers of the new minecraft with the "split screen"

When I try to enter the servers of the new minecraft with the split screen I can not play with the 2 screens so I go in one side that is control 1, the other only gets the loading screen and does not load anything else on the network server of the lifeboat. I can enter both sides normally more on the servers inpvp and mineplex only 1 side enters the other does not enter .

minecraft better together