"Internal Exception: java.net.SocketException: Connection reset"

I decided to buy a Realms server for me and my friend and I'm the only one with a problem of spawn chunk not loading on time/not loading at all. It takes A LOT of tries to actually join the server without falling below the map. And I'm the only one having a problem with it. It happens when I join the server or use Nether portal. Otherwise everything works perfectly well, no connection problems etc. 

Here's a YouTube video of it happening:  https://www.youtube.com/watch?v=PvAH8WAHPx4