None of the below information is require

Device

Redmi 4A

Operating System

Android Nougat

My Question or Issue

Triple click of earphones control button doesn't go to previous track anymore. This seems to have happened since an Android update, cause it troubles me in every music app. 

If this has also happened to you, I have found somewhat a solution.

All you need to do is download an app named Button Mapper in Play Store, then follow all its instructions and also enable the feature "Screen off actions" in it (this requires some easy steps using a PC).

Go to Headset Button and customize every button however you like. If you have a single button like me, assign functions to Single Tap, Double Tap, Long Press. Since there is no Triple Tap option for me, I have enabled Long Press to act as a Previous Track function. This sacrifices Google Assistant but I don't use it anyway.

This was the only app available that worked for me, but any suggestions are welcome!