From MarkPAman
“n the scenes section, do a reset on the desk to clear any stage settings that may be there.
Plug mic into Chan 1, Select Chan 1, (PFL Chan 1 for good measure). The Gain control on the screen should be Red. Check USB button has not been pressed.
Listen on headphones (make sure the headphone volume is up), turn up Chan 1 Gain if necessary.”
This solved the problem