I'm using Windows 7 (not by choice) and Edge Canary 80.0.323.0. All other web apps work fine. This behavior started happening a month or so ago. I've tried deleting the web app and still nothing. Anyone else having this? Is there a workaround?
@HotCakeX Thanks but dark mode in Outlook isn't the issue. Maybe the below will better describe it. The title bar isn't black even though both Edge Canary and Outlook are set to dark mode. In all other Edge web apps, the title bar is black. Even when going from Excel Online to Outlook within the web app the title bar changes from black to gray.