SS22 Incendiary Round Shotgun unlocked but cannot equip

I unlocked the SS22 Incendiary Round Shotgun in the Assualt Assigments. I was then dissapointed that I can not equip the weapon and thus cannot complete the challenges final parts. Shame as I was looking foward to burning my fellow gamers  ;-/

I logged the call and this has been passed on, but is now marked as 'No fix Available'

Anyone else have this issue?