Got funny issue like this, my brake lights and reverse lights flash when I put either signal on, as soon as I step on the brake they all quit, and just solid lights on all the lights but dim, If I removed the middle bulb on both sides signal lights flash on the bottom tiny bulb only, top light stays on but goes off if I step on the brake. Cab brake light is unaffected, no liscence plate light. Bulbs are all good. 2003 HD 2500 with the three bulb lights and small marker light at bottom. Grrrrrrr.. (new junction block didn’t help)
