Hey buddy,
I have just been through the exact same frustrating thing. It is indeed incompatibility with Catalina.
I wish i had seen this sooner: https://helpcenter.steinberg.de/hc/en-us/articles/360010273659-macOS-Catalina-product-compatibility?_sp=c600a4fc-2df3-45c6-9148-cf027e7cc32e.1586496568816 <----click software on this page. 9.5 definitely not compatible with Catalina
This article states that 10 is compatible with Catalina, but I am having the exact same issues with both 9 an 10 on Catalina.
I’ve downgraded to High Sierra for now. To be honest, I like it better, anyway. It doesn’t have that annoying access control first introduced in Mojave and tightened further in Catalina that adds unnecessary complexity to some basic things like installing things I want to install.
Anyway, you will need to do a clean install to downgrade. Here’s the download link for Mojave. How to download and install macOS – Apple Support (AU)
Once it’s downloaded, put it on a USB and kick off a time machine backup. Then, boot into recovery and wipe your hard drive. (don’t forget to go to the view(?) menu and make sure all drives and devices are visible) select the top layer drive and erase.
Now reboot into the boot selector holding Option. Select the USB you’ve copied Mojave onto and away you go. Once it’s installed create a throw away user account, then go through the drudgery of Migration Assistant to bring back the original user account and all of your apps.
Hope this is helpful!