Need to sell accessories (rings, amulets, banners) from spider den. NOT artifacts from campaign. 

I did. Still no change in the number. 

There is a challenge that has you sell fifty accessories, but no matter how many I sell the number stays at 11. I have tried selling them immediately after a campaign, and also from the accessories screen; neither works. 

Broken for me as well. I sold 11 rings and then went wait. I better check if I'm getting credit before I sell 49 more accessories seeing as that's 50+ spiders den runs. Sure enough. Broken quest and didn't get credit for any of them. I feel sorry for anyone that went and sold 50 of the accessories for the quest if they didn't have a big supply of them. Running spiders den 50 + times to replenish that is ridiculous seeing as half the time you get mystery shards or xp brew drops. Once again they dropped the ball on a weekly quest which is a PAID SERVICE. Better be reimbursed for the 11 that I had to sell and got no credit. Could have kept them. Was only selling them for this silly quest

Worked for me. Try closing the game and opening it back up.

Hi, Guys!

You have to restart the game, then it'll count them.