Headlight dash warning, periodic flickering

[N S]

Thoughts? Warning states check brake lights, they are all working. I do notice flickering of the ftont lights approx every 20 min or so, not full on/off, seems more like a pulse. My only recent work was removal/installation of the front bumper to replace the lower mesh/plastic grills.

Car has 109k mi, lights stock, except halos, replaced 5 yrs ago

[N S]

tail light grounding issue?

[N S]

Ok, pulled tail lights and saw arcing, sanded, filled with solder and still experiencing - no more rear brake light warning though. Is there something I could have pinched or undone on the front bumper?