Hi Roger, sites often detect that you have pasted text and try to clean it up. But if you disable detection, things often break on other sites, so it's not an ideal situation.

Does it work any better/differently if you paste unformatted text (Ctrl+Shift+V)?

Thank you for your suggestions.   Not sure what I did, but now when I 'copy' and Cntrl Paste, it seems to include the 2 spaces after a period!!!  Maybe Firefox was reading my online efforts to find a solution?  If it reverts back I'll notify you.  Roger