Cannot enter the caves to finalize Metheus / server disconnects us [PS4]

Dear Team,

Brief description: We are "disconnected from the server" (error msg) after completion of Metheus puzzle everytime we are trying to enter the caves.

Here goes my story: I have been trying to finish Metheus puzzle with my friend. After we successfully did the first part (the browser puzzle part) we created new server and aim to enter the caves in order to progress further (find the ancient chest etc.) but suddenly - after opening the caves entrance - Loading Screen appeared and after few more seconds I received notification "You were disconnected from the server". My colleague had no issues with accessing the caves but I couldn't get back to game. So we have been trying to troubleshoot (get back to previous day etc. with no success) and finally I am "disconnected" after every try - same happens with another colleague who joined us.

So I took another chance with another colleague: done the puzzles, second colleague has created the server and we enter the caves afterwards. Result: the same "you were disconnected from the server" error message.

I have also additional question - very important, and I did not find any answer to this:
- Do we need to create new server after the puzzles are done? -