screen brightness issues X220

[pharao111]

Hi,

recently my X220 started showing a strange behavior when I turn it on or also when i unplu it from the power source or also when I unplug it from an external monitor but on a randomized behavior. The screen color first is extreme bright and it is impossible to read anything on it. it's if the white balance is totally messed up...it takes several seconds (up to 2min maybe) to turn normal again...
i don't know what caused it but I did recentlz update my system with the latest thinkpad drivers and the usual windows updates as well...

it's a weird issue therefore i don't know how to describe it in other words...

thanks for your hints in advance!