and the secret is "Press Shift+Enter to start a new line" !
This new "press enter to post your comment" thing worries me. I can already feel an accidental nudging of the dastardly key leading to a message I didn't want to usher into digital actuality and a harassment lawsuit or two.
It's been like this for awhile now. So who uses paragraphs in FB? paragraphs, punctuation, correct spelling, all things from the last century!