Sometime after Photoshop 2021 was fist released, I started having problems with the "Save As" TIFF with LZW compression. When I get done a Photoshop composition, I "Save" and "Flatten" and "Save As" first as a JPEG (which is Joint Photographer's Editing Group compression on TIFF) and then "Save As" ad TIFF with LZW (Lempel-Ziv-Welsh) compression. With Photoshop 2020 and before, the resultant TIFF would read into any other program (GNU GIMP or Pixlr) or be plotted correctly, but when Photoshop 2021 was released, the TIFF LZW files appeared corrupted in another program or as the Windows 10 thumbnail. Only one colored Layer would appear in the image, just a flat background tint with no in-content graphics, and usually the background color flat tint.
The solution, for now, is to "Save As" a JPEG and "Close" the file, then (re) "Open" the JPEG and write out a TIFF LZW. Can someone look into this and verify and please put in a report in to the Adobe Photoshop team? Thanks.