Screen sometimes blends out (getting darker)

[ni_hao]

I recently bought a 47pfl6877k/12. I only use the TV with my HD sattelite receiver so no antenna cable connected to the TV.
I upgrade the software to QF1EU-0.150.48.13.

My problem is that when I use the menu of my satellitereceiver sometimes the screen is getting darker and the menu options are difficult to see. It is not at all menu items: some are good, some are getting too dark.

I switched in configuration the light sensor off but unfortunately.

Of course I tested it at another TV to be sure that it has nothing to do with my receiver. At other TV's everything is working ok, so it must be a setting in my 47pfl... TV or a software bug.

Question is: how to switch it off so that the brightness of my TV screen will not be changed when using menu items from my satellitereceiver. Any help will be appreciated.

Later:
for some reason I can not update the firmware with the online software update feature (no new releases found). So unfortunately I had to update the firmware by using a USB stick. I now have I updated the firmware by using an USB Stick so my current firwmare is now QF1EU-0.150.82.0. Problem with darker screen is not solved so it still exists

[Cookie]

Try to switch off (or set at MIN) the picture "improvements" like light sensor, dynamic backlight, perfect contrast, etc. and try again.

[ni_hao]

@Cookie: tnx for replying. I can of course switch off a lot regarding picture but then I will have a black screen....lol
So switching off things like dynamic backlight, perfect contrast, etc. is not the solution. I think there must be one setting which will prevent my screen from getting darker. While other things like a sensor for ambilight led's should continue to work properly or... So question still is: how to prevent my screen from getting autom. dark while ambilight feature reacts properly at light-changes.