Rick, if this is an iOS device, perform a "Reset Network Settings" under:
Settings->General->Reset->Reset Network Settings
At first I could only attach to One H9, and only some H9's were even being discovered. After the Network Reset (which will also log you out of a WIFI session), both iPad 1's saw all four H9's, and I could Pair any three H9's I wished. Of course, I wished to Pair only two H9's with each iPad.