Sound not going out to 4k monitor ? Why ?

[soamz]

Hi, I have a 2015 late MacBook pro retina and its connected to my new LG

Now my audio isn't playing out to the LG monitor.

See my system preferences.
What am I missing ?

Why audio is not coming out ?

Even my LG preferences audio is full 100%

 

[PBG4 Dude]

Sometimes I have to force the connection in Audio-MIDI Setup. Look for Audio-MIDI Setup under /Applications/Utilities .