Good?!?!? news... When I erase (first test was with DVD), it fails. It comes back from OK in just 3 seconds. I will be able to debug this more now.
I erased over and over, changing from your bad CC3D to my good CC3D (which has your bootloader and firmware) and the bad CC3D always failed and the good CC3D always worked correctly.
It is either bad data in the CC3D settings (with hardware OK) or it is bad hardware.
Edit: 2020/07/27
Fixed!!! The hardware wasn't actually bad, but has a different brand of flash memory chip. The code table that holds different commands for different brands of flash memory chips had a 4k erase command in it when it needed the 64k version of the erase command.