Damnation Chant Shire Scepter 80% dmg when Shapeshifted mod dissapeared after purchase

I bought a Damnation Chant Shire Scepter with the 80% dmg when shapeshifted mod, but only to find the mod missing after I bought it.

Attached is the screenshots of the Market listing and the Sceptre in my inventory.

https://ibb.co/B5mMbkKb
https://ibb.co/Mkhv6rvr