I am having an intermittent fault with a combination of equipment. Using A6600 camera with a Sony 50mm F1.4 A lens (SAL50F14) via a LA-EA5 adapter. Set up the shot and set the exposure (any method), through the viewfinder the image is perfectly exposed, but take the shot and the displayed take is under exposed by 1-1.3 stops. It is obvious in the view finder something is wrong as the image brightness drops and returns to normal once the preview closes. It seems to happen only where there is a lot of sea or sky.
It doesn't happen with any other A mount lens with the adapter or with the 50mm A mount lens on an A55 body (A -mount). The A6600 is fine with all e-mount lenses.
