Ok! I'm on the case!Ben, it's still adding a blank line on my desktop system - Win 7 & Firefox 62.0.3
(This line was added afterwards with just one line above the previous one).
It's not a big deal as I can work around it; in fact, I've kinda gotten used to doing so now.
Update: if I add a new paragraph without a blank line above it, it doesn't add a line, but...
if I add a single line, it adds a second one.
Just as above