I have the same problem from today. If any devs/admins can take a look at my account as well I would be grateful. The only difference is I am on the first mission and managed to equip 1/2 ATT characters with ATT % primary stat. The second character is not registering for the completion of the mission. Aditionally I lost like100k silver trying to figure out the problem. This one is especially annoying because I have cleared all missions to 100% after this one, but I cannot procceed to unlock them. 

If either of you see this: can you post screenshots of what you think should complete the challenge for you/what your gearing looks like? Thanks.