I’ve tried twice to
tell Minthara where the druid grove is, then betray her and
face the goblin seige.
Both times, the first bugbear to arrive at the grove’s door stood in a weird spot in front of it, but just out of reach. The bugbear then spent every turn dashing but not moving.
For clarity, in both encounters I killed two of the three sappers within the first two turns of combat. The third I killed within three or four I think, which I believe impacts the order enemies arrive at the door.