Using Classic Outlook on Windows for personal email, calendar, and contact management
I have the same issue. Nothing comes up in any of the MSFT or Outlook Help.
I think I found the Save As fix, but it only works in the browser version, not in the desktop app:
In an email with an attachment, mouse over the attachment, click on the Downward arrow at the right of the attachment (should display 'More Actions' rollover)
Right-click on the "Save to One Drive" and you will get an old school right-click menu with a Save as option.
Good luck to us all!