Can't join wing/invite to wing?

[RiceDisplay]

I just started playing Elite Dangerous. My friends play ED: Odyssey while I just play Horizons.
My friend invited me to his private session, however, while playing, I couldn't join his wing. I tried inviting and he tried.

The error message goes:
"INVITE TO WING [UNREACHABLE]"
*side note: nor can I send voice comms, which isn't much of a problem for either of us.

 

[Shaurin]

Horizons and Odyssey are not compatible, but your friend can go into Horizons and play with you there.

 

[Commander Debic]

I and my partner play Horizons but since the last update we have no longer been able to group no matter what we do. We also get the UNREACHABLE error message when trying to group. Means we both need to play our games solo as group play is our only preferred way.

 

[Shaurin]

Is happening since last week, I also can't wing with anyone, but strange if you go to an small outpost and park your ship there, the other commander can't dock because is using the same spot, so instance is working, just wings are bugged, I hope they fix this in the last update.