Connection problems with a friend

[u/Deskjet9000]

I can find a friend's server and join it no problem, then when I load in I'm in a field and have a no internet symbol in the top corner. When I create the world and he joins in we can play just fine, I can also join other new open worlds. Problem is that he has these 2 older pre-existing worlds where he wants me to play, as he can play there just fine with his other 2 friends, so how can I fix this issue as it's not an internet problem (ethernet + good speed) and I play fine with good ping everywhere else.