Thank you very much for your comments Peter,
Actually it was a problem of cable length. When using a shorter cables (about 100mm) between the desoldered DWM1001-Dev board and our custom DWM1001 board, I was able to flash and debug the new code in Eclipse IDE. Maybe it is a problem of speed/synchronization used by Eclipse IDE, which is not compatible with long unscreeneed cables, but I do not know…
I attach an image of the boards used, the original but desoldered DWM1001-Dev board and our custom board, connectd by short cable.
Regards