I had used my a7 II camera the same day without problems. I attached a very new lens, zeiss 28-70 f/4, and as you can se by the photos these big black patches appeared. I looked both sides of lens and sensor, all look in perfect condition. When I zoom in the spots slowly disappeared. I can guarantee there was nothing in front of the lens. The spots seemed to change in size and area during the session. Once I came back the spots where nowhere to been seen. I am worried something is wrong and that it could occur again.

What could this be?