What is the problem?
the option to flip the webcam stream vertically has no effect. for my camera orientation to work, it needs to be rotated 90 (works) and flipped vertically (doesn't work).
What did you already try to solve it?
check / uncheck the flip vertical box. update. restart. rinse. repeat.
Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, browser, operating system, ... as much data as possible)
stock standard octoprint distribution fresh installation on a pi3. everything else works perfectly. using the raspberry pi camera.