New Outlook: Calendar view cannot open modal dialogs (e.g. new event/settings) – Mail view works

Hi blinkertoonie, your testing already points to the Calendar view layer in New Outlook rather than Exchange itself. The first practical step is to force New Outlook to update, then fully close all Outlook and WebView2 processes before reopening. On Windows, try running the Outlook force update command from Run. If the issue is gone after the update, it was likely a client-side regression. If it remains, keep using Outlook on the web or Teams Calendar as the workaround and open a support case with exact New Outlook version, OS build, reproduction steps, and confirmation that Mail view dialogs still work.