You can also add this to ‘platformio.ini’.
; set CKS mcu ID for knock off of STM chip
upload_flags = -c set CPUTAPID 0x2ba01477
BTW I have a dozen Blue Pills and the mcu cover appearance does not match the CPUTAPID. With Chinese manufactured BPs you have absolutely no idea of what your getting.
I’m still trying to figure out why USB Serial only work on some of them.
Regards,
John