Nesting Grounds invisible rare mobs

Clicked on all the nests, killed the mobs.
Encounter won't complete.
There are at least 3 rares invisible.
1 with discipline aura, another with haste and hexfont.

Don't do damage, can't deal damage.

Depth 304 Armour Encounter Nesting Grounds - Petrified Forest

another one, but after copletion.

1 summon skeletons nemesis, 1 totem nemesis who were still casting.

Same here, skeleton spawner seems to be the culprit. He stays in the ground.

Bug numbers:

3.445.944.979
3.375.903.510