I have an install of Portal 10.4.1 which I have set up with Windows authentication through IIS and the web adaptor. I have set our enterprise details through the identity store. I can successfully add users. I'm seeing strange behaviour when clicking through to web app builder apps from the front page of the portal. The web app page comes up blank - if you go to the console it says there is an an unterminated string error when it passes through the username details as JSON. It gets to the full name and then stops. The only thing I can think is that the cn in our directory have the format 'Firstname Lastname (username)' - I was wondering if it was somehow getting confused with the space and bracket after the lastname. The character number that it's failing at seems to match up to this. The other strange thing is that it's intermittent. We have two realms, and sometimes it works in one and not the other, sometimes neither, and sometimes it'll be fine for a while and then fail.
Also, there's probably a related question in how to best set up the realms - could split this into another discussion. At present I seem to need to set up two accounts for the same user - username@realmA and username@realmB. I'm wondering if this is maybe part of the problem.