I had completed all possible options I was asked to do:
-check Wowhead
-check Support Forums
-disable all addons
-turned on/off Handy Notes - Shadowland and there are no missing anima shards in the zone. I know/can confirm I needed the last 5 dungeon pieces, with the Final Toll one as not available for almost a week.
I had ran the dungeon on normal, heroic, once a day, and on multiple characters, but the shard that was supposed to be at the Final Toll section of Necrotic Wake is not visible.
Thank you.
edit:
Sorry I just noticed there are 2 shard lists on Wowhead…
Zarillion’s and Varenne’s. I ran the script to find the missing shard and Zarillion’s #36 /way 42.3, 24.02) has a different location from Varenne’s (/way 52.15 39.41). I followed Zarillion’s and found my 50th there. Is it possible there are more than 50 shards scattered all over, and the achievement is just to find 50? I’ll never know but now I found my 50th. Got my achievement. Thank you!!!