Hi,
We are using a modified version of the multi-service sample for nRF9151. Generally, FOTA updates from the nRF Cloud work well.
Once we deploy the FOTA update in the nRF Cloud, if the device is online we see the device getting the FOTA notification and starting the update within about 1 to 5 minutes.
However, we have experienced an instance where there was a delay of several days until a device picked up the FOTA, despite running and being connected to the nRF Cloud. We tried re-creating/redeploying the update in the cloud and we power-cycled the device several times over the course of a few days. But in the device log we could see the device is not getting the FOTA notification and therefore does not start the download. The FOTA just stays as "QUEUED" but never changes to "DOWNLOADING".
After several days, we power-cycled the device again for a different reason, and now suddenly it picked up the OTA. We did not change anything on the device, so we think the issue lies with the nRF Cloud, e.g. the FOTA deployment suddenly came alive and triggered the device.
The problem is very difficult to reproduce and we don't have logs. My question is: Is this a known issue that there sometimes can be a delay of many hours or even days between deploying an FOTA in the cloud and the FOTA actually being triggered on the device? Is there a recommendation to avoid this situation?
Thanks