Ok, it seems it is not that simple!
While @rovster seems to have nailed it, it might not be the only issue.
I reprinted the cube with auto calibration when room lights were turned off. Issues are still there! I even turned off the LEDs of the printer but seems that they are turned on automatically.
11)PETG, profile “0.16mm optimal @ BBL X1C”, Temperature increased to 270°C, room lights were turned off to ensure auto calibration is not disturbed.
I give up and will create a support ticket!