There is another case, where someone else pointed out the same issue but I can not find it. Anyway there was no solution.
When using VSCode with NRF Connect SDK installed the Reset Pin can not be used as GPIO if flash or erase&flash is used. Only debugging works.
While Flashing with the GUI the west command is used and Pin Reset is still enabled. How can this be disabled.
Flashing xxx to undefined
west flash -d /xxx --skip-rebuild -r nrfjprog --snr 683308700
-- west flash: using runner nrfjprog
-- runners.nrfjprog: Flashing file: /xxx/zephyr/zephyr.hex
Parsing image file.
WARNING: A programming operation has been performed without --verify.
WARNING: Programming can fail without error.
Enabling pin reset.
Applying pin reset.