Keeping brightness as set

I have a 2016 MacBook Pro 13" w/Touchbar.

I am using the built-in screen as well as an LG 4k 24" monitor connected via Thunderbolt 3 (usb-C connector directly connected to the MacBook Pro).

I am having the trouble that my screen brightness for one or both of the displays will revert to full brightness upon restart, or wake from sleep, at random, not consistently.

I don't know how to keep the screen brightness setting to stay persistent.

I do not have Night Shift engaged.

I do not have "Automatically adjust brightness" checked.

Both screens' resolutions are "Default for display"

Help is appreciated. Thank you.