No Kuva when playing "Invite Only" if you don't jump at the kuva itself?

[Dergas]

Hi! I have a friend who prefers playing with only people she knows, so she usually plays solo or invite-only matches. When we went kuva farming the other day, she defended me from the monsters while I grabbed the kuva because she is not really good at the void jumping mechanic. However, it seems that she doesn't get kuva when this happens. The opposite occurs when in public matches. If I'm defending the kuva and do not do void jumps in pubs, I still get the kuva. Is this a possible bug or just a different mechanic when playing with private games? Thanks!