You didn’t mention what type of device. Firmware updates are only received when the device connects to the cloud. This happens on every reset for a Wi-Fi device.
For Electrons, however, the firmware update only occur when a new cloud session is started. This does not happen on every reset, because it uses several K of data. It could take up to a week for your session to reset.
There will be a number of changes in the way firmware rollouts are done to resolve this issue, but I don’t have a schedule for when that will happen.