Hey!
I have an idea about what the problem is. If you are changing settings that concern the memory of an image (e.g. ‘PixelFormat’), we need to update the image data. This way, we get the data that we expect.
Check out this post: https://forum.commonvisionblox.com/t/how-to-update-driver-memory-after-changing-camera-parameters/1526/7
That would also explain why restarting the application does solve the issue 
Regards,
Silas