Split Screen and online multiplayer

Hi!

A quick question, my brother has a friend over and we all want to play together. Both of them in split screen and me joining them or vice versa over the internet.

Is this setup supposed to work? My brother and I both have ps+ but his friend doesn’t.

We tried every possible combination, the friend logging in as guest or as a local account with the second controller but nothing works. When he logs in as guest their party becomes “local” which prohibits me from joining…

Don’t know if gearbox made some bad changes here, it has worked with previous titles as far as I can remember…

Grateful for any input!

Regards