friends can't join me but i can join them

i play on ps4 and everytime i create a world my friends cannot join me, they tell me they're stuck on a long loading screen that eventually tells them they can't connect to my world. however in game it says they are there and i can see their character albeit they are frozen. this has really been getting on my nerves, they can't join me yet i can join them. my connection is good and my nat type is 2 which is the same as theirs. please help!