nRF52840-DK only executing while debugging

[timonsku]

I have an odd issue with an older nRF52840-DK, I can flash and read memory from the device just fine but no matter what version of NCS I use, it will not execute whatever gets flashed. However if I start a debugging session in VSCode the program executes just fine, using the blinky sample as a test software.

I can only imagine that in some past project something got flashed that set some wrong UICR values or disabled the DCDC etc.
I already did --eraseall and --recover with nrfjprog but that did not change anything. What could be going wrong here and how can I recover from this?

[Thomas_1]

I have the same issue with my MDBT42V module (has nrf52832 chip but not external quartz clock but datasheet says its not needed even for BLE for this module) that I am programming with my nrf52-DK. it only executes while Debugging (but if i plug out Clock and Data WHILE debugging (using JLink RTTViewer) it keeps working until I power cycle (turn power on and off) (flashing and reading works perfectly fine)