This is usually a sample rate mismatch issue. With Studio One, a Studio One song controls the desired sample rate. New Song Window choose desired sample rate. The audio hardware should switch accordingly.
If the hardware does not switch, then you will have to manually set the sample rate you want before opening Studio One. And when you create a new song, in the New Song window, choose the same sample rate.
Since you are using a Berhinger mixer, I advise contacting them to let them know that board is not switching sample rates. They may have a fix or suggestion to get that working correctly.