After replacing the passenger low/high beam bulb, I've found that the new one only seems to work *once.* Meaning that they work great when I first turn them on, but if I flick them off then immediately back on, the new passenger bulb will not light. Doesn't matter if I power cycle, pull the key, or whether the car is running or not. Once the new bulb has been turned off, it will not turn back on (for at least half an hour, but I have not pinned down the timing on that.)

My plan today is today put the other new bulb in the *driver* side and see if the behavior duplicates there, to determine if I just have shit bulbs. Based on my reading here, it could also be the ballast, so swapping those across driver/passenger would be the next step to confirm that's the issue before I pull the trigger on a new one.

I'm just wondering if someone has seen this specific behavior before, or has any clue why tf this is happening, or has any critiques to my troubleshooting plan, I am very much a newcomer to this. Appreciate y'all.

Some further details:
This are the new headlights I purchased:
https://www.rockauto.com/en/moreinfo...=11701&jsn=939

This is the video I went off of to replace it (if it matters):

 

chances are it's the igniter/ballast and not the bulb. your instinct is right, swap from left to right and then report back

 

It will almost certainly not be the bulb. Make sure you separate the igniters if you swap the ballasts as you need to rule them out also.

 

I am about to do the same thing this weekend after the bulb was shutting off and reigniting after flipping the lights.

 

Exact same thing here, lights work once then not again. Replaced the bulb and ballast only to have the problem continue.
It ended up being the igniter, there's a capacitor in there that I suspect goes bad but it's not worth trying to repair.

I used this one:

 

I can second a recommendation on that AA branded unit, there's one in my passenger side headlight.