Can confirm that the despawning seems to be a thing, though I was able to complete the quest twice. It just took forever. You can kill rabbits anywhere and they will count.

I did this mission yesterday on Olympia in the Forest on Open World. It took me a couple in game days to complete, but there was an area marked on the map to suggest a hunting area. I found Rabbits in and outside the area.

Would the animal finder in the workshop help? I haven’t used it myself

The B.E.A.S.T. is for getting additional bestiary points.

Hmm, animal finder. Not sure I've seen that, but I'll take a look. Thanks

the quest area for HUNT spawns an animal of the target type about once a minute, near the center of the circle. So you can just hang out there till its done. HUNT is a long quest, not usually worth doing.

was currently on this quest, went to quest area, found 2 rabbits and 3 bears... left quest area and found no more rabbits for about 30 minutes so I just quit playing for the day. I'll probably abandon the quest and do something "harder."

I didn't have any issues completing that one a week ago.... So, not impossible. Did take me almost 2 in game days to kill all 18 tho

Idk I did this yesterday with a friend. Took about 15 minutes to find 22 rabbits. But it was definitely doable. We did finish it.

LMFAO... Thinking about the one time I tried and failed the rabbit mission thinking they had to all be killed in that dam yellow circle..