I am running Audacity 2.3.3 on a Mac 10.13.6 (High Sierra). When I open my file in Audacity – no sound comes through my headphones. My phones are on, plugged into my USB and it shows as if it’s playing. When I switch the output from my phones to the computer speaker, it plays just fine. I shut down, re-started and made sure my mic was listed/selected in my Audacity Devices preferences. Can you help??