I have seen this issue all over the Internet but so far I haven't seen anything on here about this. So I'm having an issue with joining my sisters' world on Minecraft for the PS4 and vice versa but I'm able to join my girlfriend's world on Xbox. My sisters are also unable to join my girlfriend and vice versa. My sisters and I have no issues playing other multiplayer games together.

So far my sisters and I have tried: 

Deleting each other and re-adding as friends

We have both made sure that our PS4s were up to date for software

We have also started our PS4s in safe mode and rebuilt the database as well as updated our consoles in safe mode

We have both checked our Xbox privacy settings and made sure that everything is in order there as well

We have also tried connecting via ethernet cables on our consoles

We have also tried different Microsoft accounts

We have tried creating multiple worlds but still doesn't worked

I did try to sign into their PS4 accounts on my PS4 and I was able to join my girlfriend's world on Xbox but they're still unable to join on their PS4 

We have also tried uninstalling and reinstalling the game

We have also confirmed that both our NAT types are 2

The only thing that's left is to wait for the update that's supposedly coming next week. Any other suggestions would be appreciated.