Make sure there is only one Droidcam source for each phone, and that 'Deactivate when not showing' is not enabled in the source properties.
In your second scene, add the existing Droidcam sources instead of creating a 3rd and a 4th (which will compete to connect to the phone, and what it sounds like is happening).
Thank you. I have noticed that the Deactive when not showing box was ticked on a few scenes.
I will check it out later if it solves things.
With regards making sure there is only one source for each phone. I use Advanced Scene Switcher plugin in so my scenes blend from one to another after x amount of time. On some scenes I have Filters/Masks applied to the cameras, so I have had to make a couple of different Droidcam sources.
I.e.
Scene One - Camera 1 - Camera Full Screen with Chroma Key Filter = Source name "DroidCam OBS - P3A XL - Semi-Trans"
Scene Two - Camera 2 - Camera Scaled to Small Size with No Filter but has a PNG Mask = Source name "DroidCam OBS - SONY - NO FILTER"
Scene Three - Camera 1 - Camera Scaled to Small Size with No Filter but has a PNG Mask = Source name "DroidCam OBS - P3AXL - NO FILTER"
Scene Four - Camera 2 - Scaled for Close Up with No Filter but has a PNG Mask = Source name "DroidCam OBS - SONY - CLOSE UP"
Scene Five - Camera 1 - Camera Full Screen with No Filter but has a PNG Mask = Source Name "DroidCam OBS - P3AXL - NO FILTER"
Scene Six - Camera 2 - Camera Full Screen with No Filter but has a PNG Mask= Source name = "DroidCam OBS - SONY - NO FILTER"
Am I doing the above wrong?