So right now no one on Xbox one or Ps 4/5 can do weekly challenges.
I'm on AC Valhalla on Xbox one, it was not counting my light shield kills or any of the others.
And the bird, beard and hairstyles that I unlocked from the Ostara festival have vanished too....
Great...
Hey KingBeard! I'm sorry to hear about this! Since you're missing content along with the challenges not progressing, please reach out to our Support teams either on the Support Portal, Support Twitter, or Support Facebook. There, they will be able to investigate this in depth for you!