when steering my 2013 Ford Escape to left or right there is a popping noise - mechanic thought it was rear axle, replaced it and that did not stop the noise. He said he hesitant to go on with it, put some grease in bearing and said it might stop after a while - didn’t. Driving forward you do not hear it.
try a different mechanic.
Diagnosing a noise over the internet is pretty hard. Getting a second opinion is what I would suggest.