The AudioBox 22VSL works very well with 10.14.6.
Check your USB Cable to make sure it's still good. If your Mac is using a USB-C connection, consider putting a USB Hub between the computer and the interface to make sure it's getting proper power.
If you're looking for the VSL software that originally came with it, VSL software was discontinued for the AudioBox VSL Series when Apple made changes to Core Audio.
The AudioBox VSL will still work albeit without the VSL software.
If you're still having trouble, open a support request with us at https://support.presonus.com so we can help you get back up and running.