Battery devices (e.g. motion sensors, remotes, etc) are normally sleeping and will not respond to commands sent to them. If you send a commands to a battery device, the command will be queued and will attempt to run the next time the device is awake.
As noted below, not all devices enter an awake state after sending a message. For some devices, the only option is to manually wake them up.
For many of the newer battery devices, they automatically wake up for a short period of time after the device sends a message. You can trigger a message by activating the device (e.g. walk in front of a motion sensor, press a button on a remote). When this happens, Insteon-MQTT will attempt to send all queued messages to the device. The device is only awake for a very short period of time (seconds). So this doesn't always work.
Not all battery devices wake up automatically.
For those battery devices that do not automatically wake up, or are difficult to communicate with in such a short period of time, you can manually wake them up. To do this hold in the set button on the device until the device light flashes or you hear a beep. At this point they will stay awake for approximately 3 minutes.
If you manually wake up a device using this method, then call this command so that the Insteon-MQTT knows that it can send messages to the device for the next three minutes.
Command Line
insteon-mqtt config.yaml awake aa.bb.cc
MQTT
Topic: /insteon/command/aa.bb.cc
Payload: { "cmd": "awake" }