TBC Classic skinning bug

Doing the quest Excelsior in STV. Killed an Elder Saltwater Corcolisk and the Elder Crocolisk skin drops so quest complete. Looted the item and went to skin the mob, current skinning level 288. Skinning is not available.

On mouse over of the dead mob the name and level of the mob is displayed but no text for skinning (the actual word “skinnable” in a color based on the current skinning level). The mouse icon does not change to show the mob is skinnable.
No error message displayed about a mod causing any interface issues either.
Tried to skin it anyway and no input would start the skinning cast, eventually mob corpse despawned unskinned.

Killed a Saltwater Crocolisk shortly after the skinnable text appeared on mouse over, the icon changed to show it was skinnable, and it was successfully skinned.

Noticed this on a few quest mobs to this point, only constant it they are mobs that dropped a quest item where the quest requires only 1 of that item for the quest.