Hi,
I was suffering the same problem, but for me it doesn't look like an issue related to local machine instalation or configuration, it's more related to a 2FA matter.
I decided to enter to OWA to check the security configuration to see if there is some section related to the approved devices or some else.
The surprise was when I entered the login credentials on the OWA it asked me the 2FA (I have not configured any 2FA in my account). I had to validate from my outlook mobile app and not from the microsoft authenticator app. After that Outlook 2016 has never asked me for the password again.
So, those are the steps that worked for me:
- Have the outlook account configurated in the Outlook mobile app (Android in my case)
- Login to: https://outlook.live.com from your computer. It asks for the 2FA authentication.
- Validate from your oulook mobile app.
I hope it helps.
Thank you.