RTOS/CC1310: Weird semaphore behavior

Tool/software: TI-RTOS

Hi there, I am facing issues working with 2 tasks. The function that starts the 2 task is as follow:

void rxTaskInit(PIN_Handle ledPinHandle) {
    pinHandle = ledPinHandle;

    Task_Params_init(&rxWakeTaskParams);
    rxWakeTaskParams.stackSize = RFEASYLINKRX_TASK_STACK_SIZE;
    rxWakeTaskParams.priority = 2;
    rxWakeTaskParams.stack = &rxWakeTaskStack;
    rxWakeTaskParams.arg0 = (UInt)1000000;

    Task_Params_init(&rxDataTaskParams);
    rxDataTaskParams.stackSize = RFEASYLINKRX_TASK_STACK_SIZE;
    rxDataTaskParams.priority = 1;
    rxDataTaskParams.stack = &rxDataTaskStack;
    rxDataTaskParams.arg0 = (UInt)1000000;

    Task_construct(&rxWakeTask, rfSlaveRXWakeTask, &rxWakeTaskParams, NULL);
    Task_construct(&rxDataTask, rfSlaveRXDataTask, &rxDataTaskParams, NULL);
}

rfSlaveRXWakeTask and rfSlaveRXDataTask : 

static void rfSlaveRXDataTask(UArg arg0, UArg arg1){
    while(1) {
        Semaphore_pend(rxInterchangeSem, BIOS_WAIT_FOREVER);
        // Do stuff, then semaphore_post to let higher priority task (rfSlaveRXWakeTask) to continue
        Semaphore_post(rxInterchangeSem);
    }
}

static void rfSlaveRXWakeTask(UArg arg0, UArg arg1){
    while(1) {
        Semaphore_pend(rxInterchangeSem, BIOS_WAIT_FOREVER);

        // Do RX stuff, then sleep for 5 seconds before semaphore_post
        Task_sleep(5000 * 1000 / Clock_tickPeriod);

        Semaphore_post(rxInterchangeSem);

        // if a "Wake" packet is received, pause this higher priority task and allow the lower priority task (rfSlaveRXDataTask) to start
        if(isWakeReceived){
            isWakeReceived = FALSE;
            Task_sleep(5);
        }
    }
}

The expected behavior is to have "rfSlaveRXWakeTask" to run indefinitely, RF RX for 500ms every 5 seconds.

"isWakeReceived" will be changed to TRUE when a "Wake" packet is received.

Then "rfSlaveRXWakeTask" will sleep for 5 ticks to allow "rfSlaveRXDataTask" to continue.

When "rfSlaveRXDataTask" has done executing, it will semaphoire_post to let "rfSlaveRXWakeTask" to continue.

However, the actual behavior is:

"rfSlaveRXWakeTask" runs once, then "rfSlaveRXDataTask" runs once, sleep for 5 seconds, repeat.

What did I miss here...

Please advise.

Thanks.

Edit:

I realize that if I remove  Task_sleep(5000 * 1000 / Clock_tickPeriod);  line 14 from "rfSlaveRXWakeTask", "rfSlaveRXDataTask" will not be executed.

But "rfSlaveRXWakeTask" has to stop for a few seconds before the next loop, removing it is not an option.

Why is Task_sleep affecting the flow of the whole program?