Sorry to hear you are having connection issues. I am able to connect to my H9 on my computer running Monterey. Are you using the latest H9 Firmware and H9 Control software?
If you are having issues with the latest versions of the software and firmware, can you resetting all settings in H9 Control? This can be done be going to: Settings -> Reset Settings -> Reset All Settings. You will need to login to enter your Eventide username in H9 Control after doing this.