Hi Dan,

All previous frames were taken with the buffer already set to the 4096 max.
I have tried taking different frames bellow at 512, 2048 and 4096 but I can't see much difference.

Can you tell me more about this timing error and the qhy recommendation of using slow usb. I find it quite painful that I have to wait around 20s after the actual exposure and I really wonder why.
If I understand you correctly the dark (at least the slow one) is fine and the camera is working ok as long as I use the slow mode?