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Headlights flickering, cause?

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Here in Ottawa it’s been really cold. My Model 3 is my daily which I park at work 9-5. Of course, since update 2018.50 I’ve enjoyed leaving work at 5 in warm car thanks to the “keep climate on”. However, yesterday I got into the car and noticed that the headlights flickered momentarily. I thought it was weird but it went away. Today I got into my car and each headlight did it individually at different times (a few secs apart). They just flickered a few times then acted like normal. I’m guessing that it’s not a headlight module issue since my driver side was replaced by service. It may be the cold as it was < -18 today/yesterday. Anybody else notice this?
 
I don't think it's the cold, I think it's something in 2018.50. It's happened to me a few times since I got the update, mostly when starting up and about the leave my garage but a couple of times out on the road. Temperature was nothing special.
 
I've also had this happen to me a couple times. Lights flicker after starting the car, but seemed fine shortly after. It was cold, but it's always cold these days, so can't specifically attribute it to the weather. I had never seen it prior to 2018.50.
 
Well, when my driver side headlight module was replaced, Phil (the Tesla ranger) explained that the module has to be "paired" with the car in order to work. Initially the headlight didn't want to turn on and the firmware (on the headlight module; they have their own CU) had to be authorized to the car's MCU requiring tweaking via his Tesla laptop. This means that any part can't just be replaced without said knowledge or connection tools. I would not be surprised if the flickering is caused by 2018.50 "polling" the headlight modules for authorization/testing and that's what we're seeing. I know that 2018.50 has more security features... Tesla is offering a free Model 3 to any hacker who can hack into the car (I assume software only or through accessible hardware, aka the USB port).