I just recently purchased a 2017 GMC Yukon XL Denali, with the 6.2L engine. I noticed the stock low beams are not that bright, as well as that sometimes they produce a white output and others become yellow. I had both of my headlights with assembly’s replaced under warranty and still is occurring. Has anyone ever experienced this issue, or been able to noticeably see their headlights change from white to yellow?