I captured several Hive bases and expected Sheng-ji Yang to contact me and suggest Blood Truce (just like all factions did every time I played) for a certain price. Eventually he did contact me, but when I press "yes, switch to main viewscreen" game doesn't show further dialogue options and instead shows "answer or shut connection" menu again.

Looks like a bug. Does anyone have a solution?

Maybe there is 'sunspot activity' blocking comms, do you have random events turned on?

Events are on, but there's no sunspot activity. I can easilly contact other faction leaders.

Problem is somewhat mitigated since I can connect Yang on my own initiative, though it's a pity he suggests too tough truce conditions (declaring war on my ally).