Program freezes on SVCALL

My program is freezing at some point in the initialization procedure.

It is freezing in our function that initializes the ble stack.

This is only happening to one of my devices so I am led to believe this is a hardware issue.

Stepping through the code led to the SVCAL function, and putting a debug statement here showed it is the last item that is called.

I did look at  NRF52840 ble_App_uart_c example hangs in first start and debug mode (SDK 17.1.0)
And even without debugging (which isn't usually an issue) the program still hangs.

Investigating the sd_softdevice_enable function I found that the function definition of sd_softdevice_enable() could not be found using SEGGER's find references or find definition tools. 

Is there a hardware issue that could cause trouble with the softdevice?