Toyota Corolla Sound (Radio and CD) Goes in and Out

The sound the radio and CD player on my 2014 Corolla goes on and off
sporadically.  I can still see the display info (radio station, name of song,
seconds counting up on the cd, etc.) but the sound comes and goes.  I took it
to my service station and they said I had to go to the dealership.  I took it to
the dealership and they weren't able to replicate the issue so they couldn't
help.  They said they played with the settings (I don't think this can be the
issue as the music starts and stops at random).  It has been happening on and
off for 5 days, so I don't think it's a battery issue.  I also don't think it's the
speakers since the sound comes in fine some of the time and it happens with
both the radio and cds.  Any ideas?  No idea who can fix this if my local
service station and the dealership couldn't do it.