Hydra Queen Achievment
happened to me as well
There’s an npc that must be alive to get credit. You also must do enough damage to her as well.
It took me 2 tries to get it myself. First time, I got bronze and no credit for achieve. The 2nd time this event chain popped I had just completed exploration of the zone and did the event. I followed her from the first location, wailed as much damage as I could, skipped following here under the ship and waited at her 3rd location and wailed again. This time, I got gold and achieve
Jenny doesn’t typically die on the event, especially with a large # of participants, she survived the 1st time I didn’t get the achieve. The wiki states this is sometimes bugged though.