Internal Exception 24/7.

My friend recently created a realm, so all my friends and I could play together. But I have been experiencing some seriously annyoing issues lately. I simply cannot have an enjoyable experience with this issue. 

Everytime I join, I wait around 1 minute and I get "kicked". It's the same issue everytime and I've done everything I possible could to fix it.

The issue: Internal Exception: java.io.IOException: An existing connection was forcibly closed by the remote host.

Please, if anybody knows a smart trick to fixing it, then I would gladly hear from you.