Using a Offical Pi Camera V2.1 on a Raspberry Pi 4B 4GB on a 32GB micro-SD card running the latest OctoPrint version 1.3.12.
In the OctoPrint UI I have changed the settings under "Webcam & Timelapse" to the following: Stream URL: http://octopi.local:8080/?action=stream
When I hit "TEST" I get nothing, but if I input that address on the browser of my computer, I see the image. It's upside down, but it IS streaming, just not in OctoPrint UI.
Any suggestions as to why it won't show in the CONTROL tab of the OctoPrint UI, but can be reached via the web browser??? Also, the image is 180 degrees out (upside down).