@giladWDS , I believe i was able to reproduce the issue. It seems you cannot set the fps lower than 15fps only when you have raw preview enabled and no other streams that use ISP are running. Can you please confirm that this is the case?
If you have non-raw preview or other streams enabled like small or large video, then what happens the pipeline will actually drop frames to achieve the desired fps. So it is not ideal, that is to say that the camera is still sending higher fps, but the frames are dropped. However, the overhead for receiving extra frames and dropping them at lowest level is not too big. I will investigate if we can actually set the camera to run at the desired lower fps.
I am pretty sure that i can fix it, perhaps using the fix you already found, but can you please confirm that this is your camera configuration, if possible just paste your hires camera config here. Thanks!
Alex
