Gears 5 Crossplay Error

https://www.google.com/amp/s/www.gamespot.com/amp-articles/heres-the-gears-5-modes-that-support-cross-play-be/1100-6468534/

I know that doesn't answer your question exactly, but at least we know that it should be possible

Me and my friend are trying to do the exact same thing. And the same error is happening. Can someone please fix or tell us how to fix

I agree, like you said is a great idea having crossplay in coop campaign, just like Gears 5 has.

So far, I'd have to say Gears 4 was better for multiplayer. Gears 5 is okay, but seems lacking in maps and the "Gears Of War" gameplay feel. Not too bad, just seems a tad off from what I'm used to.

I hope Gears 5 really pulls it together in the campaign, because I felt like Gears 4 got the tone all wrong. That being said, I have yet to start Gears 5's campaign.

Lastly, I know crossplay was introduced later in Gears 4, but it's available immediately in Gears 5. Mouse and keyboard players have a massive advantage (especially in Arcade). They can easily and quickly turn and/or aim at the head. I play Arcade for fun,
but it gets really difficult when a few computer players hop in to destroy. I guess I should consider myself lucky that I can turn off crossplay in Ranked at least.

I believe you would also need xbox live on the account you are trying to play with him on. For me when I use My account I need xbox live to play crossplay games such as Gears 5 with a friend whos on xbox