I have a surface laptop 3 13". It's a week old. If I use the F6/7 keys, the display brightness can move between 10-20% on the popup. The actual screen doesn't change brightness. If I use the slider in the settings, I can move all the way. The actual screen doesn't change brightness. I turned off 'auto brightness'. Doesn't change the above. I visited a computer store. Looked at their surface laptop 3s. They also cannot change display brightness. What's the deal here?