Why headphone mode not working?

[Grizzliss]

Then I use headphones, everything about sound is good, it goes through headphones, but phone itself doesn't show headphone mode icon. My phone model: Samsung Galaxy A5 2016.

 

[anon(632115)]

I have an S6 Edge running MM and there is no icon. I recall in the past if you inserted headphones that you would then see suggested apps for use with them. This is no longer the case so your phone is working correctly