Why can’t I see previews of .CR2 files on my Mac?

I have used a number of Canon cameras over the years. In finder, if I clicked on a file name, it would show the image on the right. As of my latest Apple update (15.4.1) none of the .cr2 files show their associated images, just a black square. I can open the files with photo editors but I can not see the preview images to decide if I want to open a particular image or not. Looking at permissions I have read write access, but no image. Restarts have not worked. Problem doesn't exist on my Olympus files. .jpeg files are ok. Any way to fix this?

[Re-Titled by Moderator]