I wound up creating a whole new user profile on the problem machine and now the user is able to edit the shared calendar just like before.
Thanks to all for the input.
Best >> Joe
I have one desktop with Outlook 2016 that is no longer able to edit a shared calendar.
They can edit in OWA but only view in the desktop app.
I have tried all researched solutions, including removing and re-adding the user with rights as high as "Owner". I have also disabled cached mode on the desktop and deleted the OST file.
Any additional suggestions would be appreciated.
Thanks >> Joe