Using classic Outlook for Windows in business environments
Hello,
Thank you for taking the steps. Can you please check if both Office 365 and Microsoft Office Professional Plus 2019 are installed on the computer, by going to Installed Apps page again?
If yes, kindly uninstall the Office 365 Suite, restart the computer, and check the behavior of Microsoft Office Professional Plus 2019.
If the same issue occurs, try to remove and re-add the affected Email in it for further isolation.
Kind Regards, Myk