Delve Nesting Grounds (rhoa encounter) are bugged

First time it happened I wasn't sure. But I'm certain now on the 2nd time. It's behaving very oddly.

Clicking the 1st 2 nests didn't do anything. And then I noticed loot pop and the node complete, with 2 nests still clickable. Then some rhoas finally appeared from a nest I don't think I clicked.

Clicking the further 2 nests does eventually spawn rhoas, but only once each. Total 3 spawns I think, not 4, nor any respawning of all rhoas like the node typically does.