https://devzone.nordicsemi.com/f/nordic-q-a/73112/app_timer_start-does-not-start-the-timer-freertosHello I&#39;m facing an issue with app_timer_start. Indeed, with small values, sometimes, the app_timer_start won&#39;t start the timer. As a result, the interrupt handler is not triggering. i&#39;m using FreeRTOS, i know that app_timer is using a specific tasken-USTelligent Community 13Tue, 23 Mar 2021 18:16:10 GMThttps://devzone.nordicsemi.com/thread/301540?ContentTypeID=1Tue, 23 Mar 2021 18:16:10 GMT137ad170-7792-4731-bb38-c0d22fbe4515:2a2f9f3d-2d7b-4de8-bb7b-c1535be39e33Aurele<p>I have finally found out the root cause of the issue. It was coming from the fact that there was a nrf_delay_ms (150) in a timer handler. I guess it was delaying all other timer, and moreover, it was for sure blocking all task with a lower priority (that is to say every task as my timer task is the one with the highest priority).&nbsp;</p><div style="clear:both;"></div>