This is a public reminder to myself and those who do use macOS Catalina with USB-DMX FTDI dongles... I notice the driver I'm installing below disappears after time and I have to repeat the steps. (Typically this happens before/on the day when I run a lightshow... bläh!)
USB-DMX Interfaces not recognized, or you are seeing two of them in QLC+ and/or it is not simply working. You can also check if you have the FTDIUSBSerialDriver.kext installed on you machine or any descriptive errors with the driver by running following command in Terminal: