The board was made following your schematics exactly. I would really appreciate any help. I follow the instructions to use dfu Util. When trying to upload the bootloader file I get a message
dfll cannot open dfu device 0483
In windows 10 I get “STM Device In DFU mode” when I plug the board in with Rst and boot or boot to 3.3V jumpered together.
I do not see a COM port open like I do when I plug in one of the many original openmv H7 plus boards I have.