Make sure your Puck has a clear line of sight to your IR device. If you imagine the Puck as a clock, IR signals are sent out from 2:00 and 10:00, as well as from the Puck face. It may help to aim these parts of the Puck directly at your IR device to ensure that your issue is not related to range, alignment, or a blocked transmitter.
If that did not work, place your system into Manual Mode and send a command to your IR device using the Room Tile on the App home screen. Please wait up to one minute for an IR code to send.
It is also possible that there is a configuration issue with your system. Ensure that the Puck being used as the IR device’s “Controller Puck” is correct: that it is in the same room as your IR device, that it is powered (either with batteries or AC power), and that an “IR Sending” message or screen change appears when you send an IR command to your device.