We have a windows application that uses MSAL.NET AcquireTokenInteractive. We've registered the application in Azure to get a token for use with EWS. Everything works fine, and the user will not see any prompts, just a flash as the MSAL window will open and close quickly - presuming the Azure admin authorized the app, and the user is logged in or has a valid cached token.
We have a user-agent override setting for our application, and we applied the override to MSAL, and when we pass a different user-agent string (for example, to mimic Edge), everything still works EXCEPT the user does get a prompt -- in the MSAL window it will say "Are you trying to sign in to [app name]? Only continue if you downloaded the app from a store or website that you trust. Cancel / Continue " We suspect this prompt is coming from AAD.
Does anyone know why changing the user-agent string in MSAL would cause this kind of prompt?