nRF53 Device is Protected after programming and I cannot debug

[nsga333]

When i program our new nRF5340 based radio boards the program returns Device Protected for both cores on completion. It is also impossible to debug the board as my segger refuses to connect.

I found a case with a similar issue:

https://devzone.nordicsemi.com/f/nordic-q-a/75406/problem-to-debug-net-cpu-after-segger-update-and-new-nrf5340-chip?ReplySortBy=CreatedDate&ReplySortOrder=Descending

and have tried the suggested solution of:

put the following in the NET Code at the start of main:

NRF_UICR_NS->APPROTECT=0x50fa50fa;
NRF_CTRLAP_NS->APPROTECT.DISABLE=0x50fa50fa;

put the following in the  APP Code the start of main:

NRF_UICR_S->APPROTECT=0x50fa50fa;
NRF_CTRLAP_S->APPROTECT.DISABLE=0x50fa50fa;

This does seem to allow the debugger to connect, However i get a hard fault from the command.

Is there a suggested way around this issue?

[nsga333]

I have subsequently gone back into the situation where the segger reports the following: 

Any suggestions?