>... Boot pin is pulled low to ground and reset is connected to the JTAG interface (Nrset pin)) with a segger programmer - multiple times at that and can run for hours, however sometimes it code wipes.
>...The board works fine for some time, but only upon boot-up (at random, happened twice thus far) we have seemingly a code-wipe as well as a bricked chip with the RDP set to 0xFF and unable to do anything with the chip. This does not happen during continuous running of the chip.
A few weeks ago I had a somewhat similiar problem with a Raspberry Pi Zero.
It booted up fine, and I could login via ssh.
However, a few minutes after running apt update / apt upgrade, the connection was lost and the board unresponsive.
Not only that, the SD card was irretrievably corrupted.
As it turned out, the power supply was only marginally sufficient.
It was ok under lght loads, but under higher stress, the supply fell below the brown-out level, and the system crashed.
I would highly recommend to investigate and check the power supply rails, perhaps compare yours with reference designs. I'm not a hardware developer, I would add.
> An airport radar or eye level, about 200m distance from where the boards are tested might count as strong EMI source, ...
Not sure what you mean with "eye level".
But an airport radar is unlikely the cause, this is usually directed radiation, pointing upwards.
If your location is hit by the direct beam from 200m, you will have much more serious problems than just crashing STM32F407 boards ...
