Xperia 1 - screen flicker when turning on

[dmax360]

My screen flickers whenever I turn it on using power button.. It is not consistent but troubling..

[Strampke]

Does it when you restart in safe mode too?

(push power and hold the restart for a short while, you will be offered the option to restart in safe mode)

If it behaves like it should in safe mode then a self installed app is the culprit.