I tested different jumper configurations: JP4 shorted with JP5 open, and JP4 open with JP5 shorted, both with SW5 set to 0100, which according to the documentation should boot from FlexSPI quad SPI serial NOR (or octal SPI NOR in quad SPI NOR mode) when powered from the 5 V barrel jack. With SW5 in this setting, D7 blinks red and D6 blinks green, but the pre-flashed LED blink program does not run.
When powering through the USB debug port with SW5 at the default 0001 (Serial Downloader), the pre-flashed LED blink program does run as expected.
The Black Magic Probe reports “Target voltage: 3.3V” when the EVK is powered from the barrel jack, but the SWD scan still fails. When powered through the USB debug port, the Black Magic Probe reports “Target voltage: 0V” and the SWD scan also fails.