I was fighting the Goblin Devout next to the windmill
I moved in for a melee attack (Lea'zel with a greatsword) (just left clicked on the goblin)
Lea'zel had to step down from a rock to ground level to get to the goblin. She did.
As she approached to goblin, before she attacked it, the goblin attacked her.
She lost her action point (as if she attacked).
In the combat log is says:
Lea'zel used main hand attack on goblin devout
Goblin devout used main hand attack on Lea'zel
Lea'zel was hit for 5 bludgeoning damage. (opportunity attack)
Maybe the path Lea'zel took towards the goblin caused her to enter and immediately exit it's attack range thus triggering an attack of opportunity, and breaking her attack sequence.