Using Classic Outlook on Windows for personal email, calendar, and contact management
So after seeing the post concerning above, "Modern Authentication Methods now needed to continue syncing Outlook Email in non-Microsoft email apps" I decided to upgrade to Office LTSC Professional Plus 2021. Bought a Groupon for $25. I installed this version 5 days ago and have not had a single prompt from Microsoft for my password. Everything works great now! I did not follow the uninstall instructions from the reseller but let the Microsoft app, Microsoft Support and Recovery Assistant do the uninstall of Office 2016. Nearly all of my Office 2016 customization's were keep intact. I found this app when Office 2021 could not upgrade from Office 2016 because of the click to run versions. An error message pops up and there are links to the Support and Recovery Assistant.
Very pleased with the Office 2021 version with repeated NO password prompts.... I also never had Adobe Acrobat PDF installed and was having the password prompts issue with Office 2016 all the time.