headphones not working with MacBook Pro

Using audacity 2.3.1
MacBook Pro OS Mojave 10.14.6

have checked all connections for “external headphones.”
Headphones work with everything EXCEPT audacity. What in the world?
Have tried connecting headphones prior to opening audacity, after audacity, have checked rates (44100).
I give up.
Does anyone know how to get headphones to work with audacity.
For the love, just shouldn’t be this hard.