Brake lights not coming on at the same time

I just noticed this, the left side brake light is about 500ms later than the right and 3rd brake light. This is very strange and never noticed this on any vehicle. I noticed this after parking in a garage and saw the reflection on the wall, then had other friends noticed this too. It is more pronounced on light braking. Just wondering if any has this issue or anyone has a wiring diagram. 2017 TRD Sport 2WD.

 

Or the switch...

 

Swap bulbs L to R and see if the problem follows.

 

I have swapped bulbs and the same problem. It did not change sides.

 

Electrically speaking, it has to be a contact problem. There can't be anything in between the two bulbs other than wire. Remove bulbs, check continuity (as in actual resistance, which should be less than 1 ohm), visually check for any type of corrosion, clean the contacts, possibly install a little bit of electrical contact grease to prevent any future corrosion...

 

I have check the connector no corrosion very clean the bulb brightness is the same on both sides. I was wondering if the brake lights are grounded from a computer/multiplexing reason for a wiring diagram. If the multiplex system is sending a grd. signal to the bulbs then a computer maybe at fault causing this issue. This truck has less than 4k miles on it. I don't want to send to the dealer due to them causing other issues down the road.