Lightroom Classic TIFF Color Shift

I've been using LR Classic for a few years, and I've never noticed this before, but here's what I'm seeing right now...

I'm editing some photos of the night sky (hello Neowise right? Haha). Anyway, the photos are roughly monochromatic in nature. When I'm done editing, I export a TIFF, and compare it to the LR window where I do my editing, and they're not the same. I don't mean like I find a couple stray pixels. I mean the hue is off, the contrast is different, the grain is way off...

I've tried the experiment with various color space settings in the export dialog box and always the same result.

Whats more, when I import the TIFF itself back into LR, and compare the histogram of the TIFF to that of the original, those are different.

Adobe support told to reset preferences. Didn't do anything.

Also, to clarify, I'm viewing the TIFF and the LR window on the same monitor, to take that out of the equation. Really though, I think the histogram speaks for itsef. So!  Who has an idea what I might be missing? I'm not a pro at this so it seems like something a power user would know the answer to straight away.  Thanks!

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