hi everyone. newbie here. I was using my Kurzweil pc88 to connect to my mac using the presonus audiobox itwo. with no warning it stopped sending midi messages. I can still connect audio source such as a microphone, but no midi from the keyboard. I have an Akai mpk mini with usb out connection that connects to the mac, but no go with the kurzweill nor an old yamaha portable with midi out. Presonus says talk to apple but haven’t been able to get through to them. help! I need to use the kurzweill as a controller.