I have some mysterious flicker that I'd like to troubleshoot. About 3/4 of the way through my sequence, there is what looks like contrast flicker near the middle of my frame. Little is changing in the frame, no flashing lights, and this is not cropped. The profile is Camera Standard. I have no active gradients, and used no clarity, dehaze, highlights, shadows, or any of the other flicker-inducing adjustments. See the two attached screenshots with different reference areas.

I've gotten pretty good at figuring out flicker, thanks to your help, but this one has me stumped. Any ideas?

Thank you,
Don

From what you write I assume you have watched Expert Tip #5, if not, please do so: https://lrtimelapse.com/tutorial/expert/
I'd bet to 99% that Lightroom is introducing this.
Initialize the sequence and create Visual previews without any edits. If the problem is gone, you know what to do: try to narrow down which tool is causing the problem as explained in the video.