This page can't be displayed - Turn on TLS 1.0, TLS 1.1, and TLS 1.2 ** But TLS is already turned on.

Question

I have a user that when they try to log into Duke Progress Energy's website at https://www.progress-energy.com/app/loginregistration/login.aspx it will redirect them to a "one time authentication" page which requires them to use a one-time key
to log in on a new computer.  When going to this one-time website (secure8.i-doxs.net) it will get an error message that says...
This page can't be displayed
Turn on TLS 1.0, TLS 1.1, and TLS 1.2 in the Advanced settings and try connecting to https://secure8.i-doxs.net again.  If this error persists, contact your site administrator.
Well, I'm the site administrator and I can confirm that TLS 1.0, 1.1, and 1.2 are all enabled and forced by GPO.  Restarting IE and rebooting did not help.  Chrome and Firefox both work flawlessly.
Edit: This is IE 11 on Windows 8.1 Enterprise.

Answer 1

Well, I'm the site administrator and I can confirm that TLS 1.0, 1.1, and 1.2 are all enabled and forced by GPO.
Often such messages are just a default best guess of how to explain a problem symptom.  Have you checked that the message is properly reflecting the condition that was detected?  FWIW first I would use the Developer Tools to see
what the transaction (request and response) really is.  E.g. it may be that the host is sending an HTTP response code which might be interpreted the way that the message is showing.  Then the problem would be on the host to ask: why is it sending
that code.  Often the answer is that the host is just getting mixed up about the capabilities it assumes a browser has without having actually tested them.
FYI
Robert Aldwinckle