I think it is game design that you do not get what you need. I have the same experience.
Probably it is best if you reskill to something else for a while, do 2-3 runs until you get the bow and then respecc to Bow again.
Yeah. If you say so
Try this: let you Blightmoth Dust (or something else) run out. The stuff you need for the Topaz Attunement potions.
Then farm blightmoths, you will only get death motes.
Now buy a few so yoi have spares. Sell all your death motes.
Farm again: you only get Blightmoth Dust now. No motes.
It was like our healer never seeing Will of the ancients and a guy in our group gets one like every run but would never heal.
Other games solve this by making loot tradable within the party for 1 hour or at least inside the dungeon if they were there for the kill. Not NW they would rather stick to archaic methods cuz “might finish in a week and then what”