MSP430F6779A: Can CPU OFF in the Status Register be set automatically after the Vcore shuts down?

Hi,

I have question about the CPU stop execution in the situation steps below (voltage supply not stable).
1) DVCC > 3.0 V
2) Vcore settings PMM_setVCore(PMM_CORE_LEVEL_2)
3) Setting the MCLK frequency to 16 Mhz.
4) DVCC drops to 2.1 V
5) MCU stops processing (suspect CPU OFF bit = 1)

Because the voltage at the Vcore pin was measured as 1.92 V.

Can CPU OFF in the Status Register be set automatically after the Vcore shuts down?

User guide info

Some source code

mclkFreq = ((uint32_t)16777216)

PMM_setVCore(PMM_CORE_LEVEL_2);

UCS_turnOnLFXT1(UCS_XT1_DRIVE_0, UCS_XCAP_0);

UCS_initClockSignal(
       UCS_FLLREF,
       UCS_XT1CLK_SELECT,
       UCS_CLOCK_DIVIDER_1);

UCS_initClockSignal(
       UCS_ACLK,
       UCS_XT1CLK_SELECT,
       UCS_CLOCK_DIVIDER_1);

UCS_initFLLSettle(
        mclkFreq/1000,
        mclkFreq/32768);