Unable to Log In on IOS devices

I am unable to log in using specific credentials on any IOS device.  I am able to log in successfully on an Android device (Galaxy 7) using these credentials.  When trying on IOS, i often got a 401 unauthorized, (Ping logo at the bottom of the page).  I have tried with and without Azure Authenticator installed and it makes no difference. 

I was able to use an account from a different company on the IOS device and that account does log in, and automatically places the account in the Azure Authenticator App also.

Any thoughts?