There are a couple of things you can check.
Power up both boards within around 10 ft of each other and ensure antennas are connected on both units. Give them 20 seconds or so to see if they establish communication. If they do then it is a range issue in the installation.
If the units do not communicate in close proximity then leave them powered up and inspect the bottom of the boards. You will find a copper wire on the bottom which acts as a heatsink for the wireless modules on the board. Use your finger to inspect their temperature. It is normal for them to be warm but if they are too hot to hold your finger on them for an extended period then the wireless module is damaged and is drawing too much current causing the heatsink to overheat. This will require warranty repair. You can fill out an RMA form here: Log In ‹ ncd.io — WordPress
If the heatsink is not overheating then power the boards down and pull the wireless module out of the board. Look at the bottom of the modules. You will see 2 rows of 10 pin headers. There may be riser strips installed on those 10 pin headers, if so pull them off. Now install the module back into the board ensuring the metal pan on the bottom of the module does not contact the 5 pin female header on the board, you can just not press them all the way down or use electrical tape to insulate the metal pan. After doing this to both boards attempt your test again.
If you have any questions on this please let us know.