Sometimes it took my boards two or three times to take the bin and rename it to cur.
Combination of M997 and resets would have to do it. Also, sometimes when I transfer the bin file it is "empty" (0 bytes) after first read and then the board is "dead" until I retransfer the bin and do a reset via the board reset button and not the lcd controller reset.
On the note of usb connection issues, I found that for my mks sgen L boards (similar to the skr 32 bit) I had to define the first serial port as -1 and the second serial port as 0 and this allowed me to use the sdcard on board for firmwares via usb connection as well as usb control.
