I have started having an issue where the Teams Meeting option is not showing up on the ribbon with using the Outlook calendar (three computers so far). It appears the add-in loads correctly, but the icon is not on the ribbon.
I have uninstalled both MS Office and Teams and reinstalled. I have also made sure the load behavior in the registry is correctly set to 3. Two fo the three computers started working out of the blue. The third one the Teams icon is still missing.
I also went to %localappdata%\Microsoft\Outlook\ deleted all the data and started Outlook again. Nothing. The Teams Meeting option is still not showing.