I have just downloaded Survey123 to my PC and iPad.
I am unable to login to the app via my ArcGIS Online account, even though I am able to login via the web on the computer and through the Collector app on the same device. The error message is "Unable to generate token. Invalid username and password."
In a seperate issue, the desktop applicaton for the software will not display correctly. When opening up a survey, the error message displayed is shown in the image attached.
It may have something to do with my downloading and setup.