Can’t login into adobe fill and sign

I attempted to log into the mobile version of Fill and Sign. I put in my username and password no problem. The boxes appear to put in the verification code but disappear very quickly before I can put it in and I get an erro message saying "Sign in operation failed."  It happens on my iPad Pro latest version and my iPhone XS Max. All of my software is up to date. I have also tried deleting and reinstalling the app multiple time. I am able to sign into all of my other Adobe Creative Suit Apps.   Please help! This has been going on for months I have made calls, chatted with costumers service techs to only be given the link to the community forum.