I found a strange issue with the MKS robin nano board in the saphire printer.
I originally install an early 4XX build I forget exactly which version, but it flashed with the Robin_nano35.bin filename. When I upgraded to 488 it would only flash with the name Robin_nano43.bin
I just upgraded to 586 and tried Robin_nano35.bin and Robin_nano.bin both failed to flash. It did flash with Robin_nano43.bin though.
Just to clarify, I originally thought that the numbers in the filename were expressing the screen size, my printer shipped with a 3.5 TFT screen. This does not seem to change what the bootloader is configured for though.