To eliminate any issues due to starting focus point, you should start you first autofocus sequence with your best focus point (if you have a bahtinov mask use it to focus your system). Check your mechanics settings : initial step size and out step multiple to be sure that the first capture always show a few stars identified by the search star algorithm. To do that, after a good manual focus, move your focuser using (initial step * out step multiple) and take an image to verify star size and star detectivity.

Joe.

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