Game crashes when adding 2nd player to Star Wars World (Only)

Recently purchased the Star Wars pack for my 2 sons. We created a world using the pack, and it works fine in single player. However, as soon as a second player is added, the game crashes with error ce-38700-8.

Both the game and PlayStation have been checked, both say there are no updates available.

 

This happens every time, within seconds of adding the second player. We have tried;

Deleting the save and creating a new world (several times)

Trying several different accounts; PSN account that has been linked to Microsoft, PSN account that hasn't been linked to Microsoft, and local non PSN accounts. Each do exactly the same.

 

Unlike issue MCPE-160716, we are able to play multiplayer split screen in 'normal' Minecraft worlds without any problems - this bug only exists when we attempt to do multiplayer in Star Wars worlds. Please do not mark this as a duplicate.

Please can you help?