не в переменной дело
void IRAM_ATTR detectsMovement()
{
// bMotionOn = true;
}
vTaskStartScheduler();
xTaskCreate(ThreadA, "Task A", 1000, NULL, tskIDLE_PRIORITY, NULL);
attachInterrupt(digitalPinToInterrupt(motionSensor), detectsMovement, CHANGE);
attachInterrupt(digitalPinToInterrupt(motionSensor2), detectsMovement, CHANGE);