(I'm not good for English)

My friend can't join to my world. I have tried to sign in again to my account, switching connection, and make new world. But my friend can't.

Conversely, I can join to friend world, realms, official servers too.

3 months ago, they could join to my world without problems.

By the way, my friend can join when they use LAN connection.

Sometimes they can join but moving fast bug has occurred.