XF1 - same settings, different exposure

I hear you about the temperatures...

Regarding the Fuji sticky aperture blades issue - this case is the opposite.

In the sticky blades, images are over exposed more and more as your settings
define a smaller aperture - then the camera fails to close the blades and too much
light travels through the lens, right?

Here, the exposure gets worse as the aperture is larger,
since the issue in in the shutter failing to adhere to the required speed
which gets higher and higher according to the aperture setting.