TMS320F280025: EPWM4 Interrupt stop after a while as TI diagnostic function run

Hi

My project using TI AFE031 FSK boostxl_afe031_f28004x_rx as template. I just change the interrupt source to EPWM4 as below

#pragma CODE_SECTION(epwm2_isr,".TI.ramfunc");
__interrupt void epwm4_isr(void)
{
    EALLOW;

    //
    // Enable ADC ISR Nesting
    //
    uint16_t TempPIEIER;
    TempPIEIER = PieCtrlRegs.PIEIER2.all;
    IER |= M_INT1;
    IER &= MINT1;                         // Set "global" priority
    PieCtrlRegs.PIEIER2.all &= MG1_1;     // Set "group" priority
    PieCtrlRegs.PIEACK.all = 0xFFFF;      // Enable PIE interrupts
    asm("       NOP");                    // Wait one cycle
    EINT;                                 // Clear INTM to enable interrupts

    //
    // Run the FSK Correlation Detector Function
    //
    FSK_CORR_DETECTOR_OverSampl_RUN(&FSK_struct1);

    //
    // See if a mark or space bit is detected
    //
    if(FSK_struct1.bit_detected != 0)
    {
        rxMessage[message_index++] = FSK_struct1.bit_detected; // Save the detected bit in the message buffer

        FSK_struct1.bit_detected = 0; // Clear the detected bit member

        //
        // Set flags when message buffer is full
        //
        if(RX_MESSAGE_SIZE <= message_index)
        {
            message_index = 0;
            msgFull = 1;
        }
    }

    //
    // Clear INT flag for EPwm2
    //
    //EPwm2Regs.ETCLR.bit.INT = 1;

   EPwm2Regs.ETCLR.bit.INT = 1;

    //
    // Acknowledge this interrupt to receive more interrupts from group 3
    //
    PieCtrlRegs.PIEACK.all = PIEACK_GROUP3;

    //
    // Restore registers saved for ADC ISR Nesting
    //
    DINT;
    PieCtrlRegs.PIEIER2.all = TempPIEIER;

    //
    // Toggle gpio pin for measuring frequency, debug purposes
    //
    //GpioDataRegs.GPCTOGGLE.bit.GPIO65 = 1; // LP Pin 47
}

and

#define INTERRUPT_BIT_ISR &epwm4_isi

interrupt_register(INT_EPWM4, INTERRUPT_BIT_ISR)

Anything was working fine as long as I added TI diagnostic function code which is reference to diagnostic library example f28002x_test_application.c

            DINT;

            uint16_t returnVal =
                    STL_CPU_REG_checkCPURegisters(STA_Tests_injectError);
            if (returnVal == STL_CPU_REG_FAIL)
            {

                  mcuFault_Status = mcuFault_Status | CPU_REGISTER_FAULT;
            }
            EINT;

The ISR function don't be run after a while ~ 7minutes. The diagnostic function will be ran in main loop ~ every 14ms.

Please advise that did I do something wrong?