Item from Macrocosmic Orb Campaign dropped from enemy but gone from inventory

[Maiyuu]

Thread Title:
Heavy Metal Pouch dropped from BCNM mob but did not appear in personal inventory

Operating System:
Windows 10

ISP:
Telekom

Type of Internet Connection:
DSL

Internet Connection Speed:
200mbps

Date & Time:
14 Sept 2022/1600 GMT +2

Frequency:
Once: Have not seen another pouch drop yet

Character Name:
Maiyuu

Race:
TarutaruF

World:
Asura

Main Job:
Puppetmaster

Support Job:
Runefencer

Area and Coordinates:
Throne Room: Kindred Spirits II (Very Difficult) BCNM - Macrocosmic Orb

Party or Solo:
Solo

NPC Name:
None

Monster Name:
Duke Amduscias dropped the item

Steps:
While fighting, saw drop and continued until fight finished.
1. Checked inventory upon exit and couldn't find the pouch anywhere.
2. Checked chat log to see if I accidentally tossed it, and I did not (Did NOT see the message "You throw away :item:")
3. Checked to make sure I had inventory space, and I did. (Did NOT see the message "could not receive :item:")
4. Typed /itemsearch "heavy metal pouch" and said "no instances of that item found"
5. Checked Mog Sack and Case, could not find item there either.

Edit to add:
Ran Brothers D'Aurphe II (normal) with a friend and heavy metal plate dropped to treasure pool. I was able to lot and pouch appeared in my inventory without issue. Still haven't seen the pouch from Kindred Spirits II