Originally Posted by MK3_TX
Between the two buttons in front of the light towards the car,one is to turn on all the inside dome lamps...the other to completely turn off all of them even with the doors open. The big button on the backside of the front dome lamp is for the front light only. I know my experience was if you have the domes set to " off" and press it again while the door is open it will not come on . You have to close all doors and when you reopen it they will come one . Hope that makes sense ,sitting on the toilet typing this on my phone !
I suspect this is probably it. After work tonight, I did a few tests with hitting buttons while the door was in either open or closed (but never both at the same time). I found that there is a correlation between future dome lamp behavior and the state the door was in when pressing the buttons. For the rest of the evening, the dome light behaved as expected - it turned on when unlocked the car using the fob, and turned off after all doors were closed.