Yes I've seen this.
I was wondering how to test.
I can see that left and right break pins are on separate connectors of the LCM.
So I measured voltage on the back of pin 14 on connector X38, when connected to the LCM.
Pin 14 is responsible for the rear right brake light. I got 12 volts.


Now I went to connector X12 on the LCM. Pin 9 is responsible.for the rear left brake light.
I measured the voltage on pin 15, which is the power supply, it has 12 volts. Then I measured voltage on the back of the connector, pin 9, and got no voltage.
I did all tests with the connectors plugged in and brake pedal applied.
Looks like LCM is not supplying voltage for the wire on pin 9.
Does this condemn the LCM?