CCS/MSP430FR2433: CCS breaks at NOP in mult16_f5hw.asm at 16MHz, and locks outside of debug too.

Tool/software: Code Composer Studio

This issue is almost identical to that reported in https://e2e.ti.com/support/microcontrollers/msp430/f/166/t/685882.

During debug in CCS, a "phantom" breakpoint occurs in mult16_f5hw.asm at the NOP; CPU19 Compatibility line (pasted in here for reference).

__mpyi_f5hw:  .asmfunc  stack_usage(2 + RETADDRSZ)
	PUSH.W	SR			; Save current interrupt state
	DINT				; Disable interrupts
	NOP				; Account for latency
	MOV.W	OP1,&MPY_OP1		; Load operand 1 into multiplier
	MOV.W	OP2,&MPY_OP2		; Load operand 2 which triggers MPY
	MOV.W	&RESULT, R12		; Move result into return register
    .if $DEFINED(__LARGE_CODE_MODEL__)
	POP.W  SR
        NOP                             ; CPU19 Compatibility   <----This line
        RETA
    .else
	RETI
    .endif
	.endasmfunc

Similar to the other poster, I am working with GPIO pins. The code essentially implements an Arduino-like interface to set GPIO pin direction:

pinMode(CS_PIN, OUTPUT);

The actual break and hang happens when executing the GPIO direction setting:

    else if (mode == OUTPUT)
    {
        *pins[pin].directionReg |= pins[pin].bitMask;
    }

CS_PIN corresponds to a number that is equivalent to the launchpad boosterpack standard. In my case CS_PIN=18, which refers to P2.2. 

*pins[pin].directionReg are defined in a struct and simply point to &P2DIR. The pins[pin].bitMask is also defined in the struct and simply returns the macro BIT2. This essentially does the following:

P2DIR |= BIT2;

This issue occurs at 16MHz, but does not occur at 12MHz or 8MHz. It occurs at the same line every time. There is no power mode changing. Outside of CCS, the code also fails to run. I assuming it is locking up at the same point.

I couldn't find a resolution in the other post or through searching.