No Air for macOS Catalina?

[CongoFather]

You'll probably solve your issues if you downgrade to the latest OS before Catalina(Mojave). Then you should install the latest Devialet Driver on Mojave. If you want to be on the safe side, enable Direct Mode on Mojave by following the steps on https://community.audirvana.com/t/direct...ve/1861/38   

After that, you may upgrade to Catalina. Finally, you can enable "Direct Mode" for better audio quality on Catalina by following the steps on https://community.audirvana.com/t/enable...na/9638/81 and bypass the OS modifications on the audio stream.

Note: On page, https://m-audio.com/kb/article/2482, and  in section "3. Things You'll Need to Know", it says 
"macOS Catalina will include a security feature that will require the user to allow a system extension when installing a new driver. This is very simple and only needs to be done once for each driver. So, if you're installing any new driver on macOS Catalina, look out for a System Extension Blocked warning and see the driver section in this article for instructions."

and adds in the following paragraph that "The good news is that this is only necessary if you are installing a new driver. If you are updating to Catalina and already have the latest driver for your device installed, you will not need to re-install the driver or complete these steps."

I think this is why I have never had such a problem like you have experienced. I had installed the drivers initially on "El Capitan". Then I upgraded to "Sierra", "High Sierra", "Mojave" and finally to "Catalina" by time.