Resolved! Reset, USB-device "BOOTLOADER" shows up, but CubeProgrammer does not see it
I've "developed" a ridiculously simple test program using STM32CubeIDE, for BlackPill STM32F411CE :on board LED blinks at 0,5 Hz. Downloaded via ST-link plugged into USB. Browsing through Memory shows the downloaded code (Segment .text) matching the...