I can confirm that connecting via bluetooth from Mohave 10.14 to my brand new H9 does not appear to work. The H9 shows up in the bluetooth preferences as a new device (With the correct serial number). Cliking on 'connect' results in long wait followed by a 'Could not connect to this device error'
Were you prompted to type in a paring passcode? Have you tried to connect to your H9 in H9 Control by clicking "Manually select a device" and "Connect via Bluetooth"?