Additionally, most newer IQ Panel 4s have an external antenna for the 319.5MHz radio.
When packaged, the antenna is typically tucked inside the panel. Make sure this has been routed out the back of the panel and is not pinched by the back plate. If the panel is wall mounted, make sure the antenna is inside the wall but not touching any metal or other wires. See the setup guide for more information:
Be sure to fully power down the panel before checking the antenna wiring.