Using New Outlook on Windows for personal email, calendar, and contact management
There seems to be a new development in the last month that has solved the problem (for me at least). Like others have said, immediately after you paste in what you want, at the end of the material you just copied in you see this:
When you click the chevron to expand the list, it gives you these new options (not the three clipboard icons everyone else is referring to above in this chain):
Choosing "Paste as is" gives me the same formating (including spacing, font, colors, etc.).
Finally!