In the Firefox address bar enter "about:config" (without the quotes). If a cautionary note appears bypass it by clicking "I accept the risk," or whatever such words appear. (I’ve routinely done that many times over the years for various reasons, without issue). In the search box which then appears enter "editor.use" (without the quotes). Right-click on the line that says "editor.use_div_for_default_newlines" and click "Toggle." That should change its value from "True" to "False."Thanks for that, @almarg! Firefox has the most part been pretty well compliant with browser standards, unlike Internet Explorer (haven’t been inclined to play with Edge). Because of this, I never thought to dig through Firefox for configuration changes.
I’m pasting this hack into my recovery document (I have a few about:config changes logged).
... Thom @ Galibier Design