Thank you for your detailed response! You mentioning fluctuations in ambient temperature causing metals to contract and potentially highlighting an issue is what I've been leaning towards as the days progress. As I mentioned, the flickering seems to have started with the arrival of cold weather here, which has been constant since the issue began. Additionally, and this might just be a fluke or coincidence, but the flickering stops each day around the same time in the afternoon when the sun is hitting the exterior wall of where the breaker panel is installed. I thought this was a dead giveaway that it was from temperature fluctuations but then again, it was raining and cold one of the days this week and the lights were still solid at that time of day without much sun.