I have this issue as well. The situation between the 2 families just randomly escalates even though I have tried everything to deescalate the situation.
I killed the robbers in the gullet but let Persa go.
I got both sides to agree to a meeting.
Ezzali tells me to go over and tell the Valera guy that she will come over.
However, the Valera guy won't even give me a chance to tell him. He just tells me that Belda has been captured and I can either join the or fight them.