Keeps saying “Unable to connect to world

Whenever I try to join me and my friends long time survival world, it keeps saying “Unable to connect to world” even after restarting my xbox twice, him leaving and rejoining 7 times, me restarting minecraft 2 times and signing out of my account 3 times, it still keeps saying “Unable to connect to world” or “Connection timed out. Unable to connect to world”. Please help I dont want to lose all my stuff.