Meijhen

2007 Honda Accord EX-L v6

I've found a couple of posts about this issue here, but none of them quite fit, and I'm stumped.
I broke my right headlight in a minor accident about a year ago. The turn signal started blinking fast shortly after that, although the light still worked. I replaced the headlight assembly, which came with a white bulb. The fast blink stopped for about 2 days, then started again.

Running lights only -- front signal works, even though it is blinking fast. I changed the bulb to an amber bulb (Sylvania 1157A, Longlife because it's damn near impossible to find the basic ones anymore) -- still blinking fast.
Headlights on -- the front signal does not work (rear signal continues to blink fast)
Hazards -- work normally all the way around.
All other bulbs are normal. Left turn signal works fine. None of the bulbs appear any dimmer than any others.

I've tried to take a look at the wiring, looking for any breaks or wear spots, and I can't see anything initially. I've seen several posts indicating this could be a faulty ground, but I can't find any information on how to identify or resolve that, if it is. Electrical work is something I am very unfamiliar with, beyond changing bulbs and plugging/unplugging things.

Is it worth it to replace the turn signal relay? Any ideas of anything else to try?