Hello,
We've had some Nintex forms & workflows in production for a few months now in our On Prem SP 2016 farm. I was about to make some modifications to the existing form and am now experiencing an issue where I get prompted for credentials when I attempt to modify a control that is tied to a multi-value look-up column. IE and Edge will prompt me 3 times for credentials then stop, whereas Firefox and Chrome will prompt indefinitely. My account is site collection administrator, so there shouldn't be any permission issues. The only change that I am aware of is that I updated the site column to pull and additional column value, but the issue still occurs if I remove this value. The site is SSL so I can't really take a look at the traffic in a network trace.
Has anyone ran into this issue before? Any suggestions on what to check?