Hello @Alex S. Thank you for reaching out to the Community regarding your issue, though I am sorry to hear that you are experiencing this.
With the behavior you're experiencing and this being direct connect I'd recommend getting in contact with USAA to see if we might be able to get more information on what exactly is. I'll leave their information down below so you can find a time that works best to contact them.
https://www.usaa.com/help/contact?akredirect=true
Thanks, Quicken Francisco
John St said: Having same issue in Italy. All other finacial institutions seem to be working fine (no error msgs) but trying to add USAA account results in Error 16. Only trying to add account because I was directed to deactivate existing accounts. Was using Express Web Connect for years but just recently visiting Italy. Worked fine in Germany, Spain, etc.