Can't offload camera cards — (Error code -36)

I recently upgraded my systems from 10.8.6 to 10.13.3. Obviously, I'm not an early adopter because my machines are workstations. When they're solid, I keep marching, not needing the fanciest bells and whistles that a shiny new OS may promise. That being said I'm having a crippling issue with offloading my camera cards. I've been all over the web, these forums included, and can't seem to find a solution.

Normally, I would go the Finder, find the '100EOS5D' folder with the images inside, rename it, drag-n-drop it to the destination and wait for the copy to complete. This is pretty obvious and has been reliable and successful for many years. Not anymore. Now when the copy starts, it does next to nothing. It may copy one or two images then balks. It then gives me the error code -36 and it temporarily ejects my card and says "Disk Not Ejected Properly". A few seconds later the card will reappear in the Finder. But it's a dead end, an infernal loop.

I've seen the talk about the dot_clean process with the Terminal. I've tried that to no avail. I saw somewhere that adding -mn to the command could help, (dot_clean -mn ~) but it doesn't for me. The cards are not corrupt. If I boot into my old 10.8.5 world, the images transfer perfectly, byte-for-byte, as expected. If I keep the card in the camera and use Image Capture, I can get the images to offload in 10.13. However, that still doesn't explain why the formerly reliable Finder copying method refuses to work — every single time.

I'm a little discouraged because of the all the celebrations over the dot_clean method since it won't work for me and the vast majority of the "fixes" seem to use this technique. I tried re-formatting the cards as ExFat with Disk Utility but the cameras don't like that and force me to Format them back to FAT32.

I don't know what else to try. I'm hoping someone has a solution that I have encountered in my search thus far. Rebooting into my old partition seems like a silly, slow workaround for something as "simple" as copying files.

Thanks for any suggestions!