Free trial. Can't play with friend.

I have the full version of BF6, and my friend downloaded Battlefield Redsec to play together during the free trial. However, when we are in a party, we can't launch any modes except Obliteration, Сasual Breakthrough (with bots), and Redsec. If we select any other mode, we get an error saying something like 'cannot play in party.' If my friend becomes the lobby leader, it says 'BF6 required.' The announcement promised 5 available modes, but we can't access them. Appreciate any help.