[old_tv_nut]

You posted an "Un-edited Tiff loaded into Affinity Photo editor" that posted as a jpg.

Then you posted an Affinity-edited tif with the setting "use document profile" but the export screen doesn't say what that profile is. When opened in Photoshop to find out what the profile is, it says it's sRGB.

So, to clarify this, how about uploading the tif here before loading it into affinity, and we'll see what the profile is when loaded into photoshop. Maybe it hasn't been confined to sRGB yet at that point. So the question is, where did it first become sRGB. If it's sRGB before editing, all is lost, but if not, there may be a possibility to set the working space in Affinity to something wider than sRGB (I don't know for sure, have never used Affinity).

If you load a raw file into Lightroom, it uses the wide lightroom working space of Prophoto RGB. If you load a raw file into Photoshop, it will use whatever working space Photoshop has been set to. If you load some other file type into Photoshop, and if the Photoshop preferences have been set to pop up color warnings, it will tell you if the file's color space and the Photoshop working space don't match, and what each of those are.

So, see if you can upload the TIF file from the camera before opening it in any software, and let's see what the color space is to begin with.