Asgard’s Wrath 2: Cannot obtain last Enhanced Whetstone

[JP-1111]

 I finished game and started maxing all weapons out.  Noticed I needed one more enhanced whetstone to finish Abraxas’ Champion Axe. There’s one quest the system didn’t check off being”Convince Thoth to join Horus’’s cause”  how can I get the last enhanced whetstone? 

[williamLo0325]

There is a whetstone in a Hidden Chest near the left side of the Temple of Tefnut in the Great Sand Sea.

[Cafe129]

Did you ever figure this out?  I am having the same problem.