I often send an image from Lightroom 10.4 to Silver Efex Pro 4 using the Edit pop-up menu. When Silver Efex is finished and I’m back in Lightroom, I can see the final B&W image when viewing in the Library, but I still get the original image when I switch to the Develop module. This only happens for images where I’ve selected the nondestructive edit mode in Silver Efex.
Sounds like a problem with Lightroom reading the info you’ve stored in the tif file when nondestructive mode is selected.