I keep having login trouble with the same pattern. At first I thought I was typing my PW wrong, but now don't think so after being super careful.
When I come back to CC sometimes I find I have been logged off. I choose log in and type in my name & PW and hit the button. The screen goes to the same login screen with the fields blanked out. I type in name & PW again, then get the ""Oops" screen. When I hit the back arrow from there, I'm back to entering the name & PW, and then it works.
Has been going on for a few weeks. On an iPhone 6 with iOS 10. Can you please look at, @CCadmin_Sorin