The preferences you quote are for when LR creates an image for external software to work with via Edit In that-software/plug-in.
Where do the TIFs come from? A D810 produces NEFs doesn’t it? Are you using other software to create the TIFs or is LR creating them?
I import my nefs into LR then export them as tiffs; I send them to my retoucher who uses PS to retouch them. We have coordinated our settings. He then sends them to drop box. I download them and import them again into LR to manage my files and export jpgs and other versions of the file.
You may have a Preset working on import.
What you describe could occur if the retoucher isn't embedding a color profile in the TIF that comes back so the ProPhotoRGB is being interpreted as sRGB.
Another scenario would be possible if the TIFs are already in LR and then you're reimporting over the top of what's there and the retoucher's adjustments have made them look quite a bit different and your monitors/displays aren't profiled very well.
That's a good idea. A variation of this idea would be that even without a preset there are different LR defaults for TIF compared to RAW and something is non-zero for TIFs.
The easiest way to tell if either scenario is occurring would be to check all the sliders immediately after import and see if they are either zeros or As Shot everywhere like should be, especially in the Basic-toning, HSL, Curve and Dehaze areas.