Question

core i5, windows 10 64 bits, audiobox 1818

After installing the universal control the microphone that I connect to audiobox 1818vsl only sounds with studio one, when I record a track

Answer 1

This is likely because the VSL mixer application is removed when installing Universal Control.

The VSL mixer is setup by default to monitor all inputs of the 1818. Once the VSL is gone these inputs are no longer going to be actively monitored unless configured for monitoring in your DAW software or other audio-related applications.