H.264 Rendering Issue, a Serious One - Impacting my Productivity

[#1]

I have a recent issue when exporting using any setting in H.264. Everything is fine in the timeline but upon rendering, I have color changes as the video progresses. I have attached some video without audio as an example. The actual colors and darkness are when the caption (graphic) is on screen. My suit jacket is grey but the video starts out very dark, then my caption appears and the picture lightens up to the accurate colors. then I cut to b-roll and when I come back, my suit is dark again. I've attached a pic of the timeline, no other effects on.

This does not happen with any other codec, only H.264, coincidentally the most important one. I have the latest Nvidia driver, no change. I rolled back my Nvidia driver to September, no change. I switched to the Nvidia studio driver, no change. I rolled back to Premiere 14.4, no change.

I don't know what else to try. Help!!

[#2]

I have a recent issue when exporting using any setting in H.264. Everything is fine in the timeline but upon rendering, I have color changes as the video progresses. I have attached some video without audio as an example. The actual colors and darkness are when the caption (graphic) is on screen. My suit jacket is grey but the video starts out very dark, then my caption appears and the picture lightens up to the accurate colors. then I cut to b-roll and when I come back, my suit is dark again. I've attached a pic of the timeline, no other effects on.

This does not happen with any other codec, only H.264, coincidentally the most important one. I have the latest Nvidia driver, no change. I rolled back my Nvidia driver to September, no change. I switched to the Nvidia studio driver, no change. I rolled back to Premiere 14.4, no change.

I don't know what else to try. Help!!