Unable to Load World on MCPE

I'm hosting a server with several of my family members and for some reason, only the computers with the Windows 10 edition of Minecraft can join while other members with MCPE are stuck at a loading screen. We used to be able to join and play with one another but now, 4/7 people who have MCPE cannot join. The console says that the server has started and the player has joined but in reality, the player is still unable to load in the server, being stuck at the loading screen. We all have the same version of Minecraft with no plugins and no cracked versions. Please help!

If we're lucky, a mobile player can join but is frozen in place, unable to move.