First heavy attack on flaming flail applies burning visually on rats all around the hitted target, but only applies the damage over time to first target.
Tested in keep with show damage mod and creature spawner mod. Also went in a mission War Camp after bots died “peacfully” tested on horde with same result.
When this happens with show damage mod turned on, it shows it did 0 damage in aoe, which is probably intended. But also shows icon of shield blocking, which might be the source of issue. And in chat it report I did 0 damage to them.
This might be allready reported, but I didn’t seen it anywhere.