Re: My screen dims to 50% automatically completely ignoring my display or power settings that I set.

Hi LazyK68,

Welcome to Sony Community!

We apologize for this inconvenience. What is the model name and the current operating system of your laptop? Have you check if the automatic brightness on your laptop. Make sure that it is disabled so that it will not overwrite what you set on your screen brightness. 

Kindly refer to this link to assist you in checking the brightness setting on your laptop.

https://us.en.kb.sony.com/app/answers/detail/a_id/44471/p/56403/kw/disable%20automatic%20brightness