The lollipop update brings in some great features but here are a few cons, as people have started using it we are seeing minor issues coming up such as this one. By default the lollipop installs sets some features to turn on, one of which is the Volume in Pocket.
Many users of the lollipop are experiencing this very same issue with volume automatically reducing even if you set it to the highest level.
This is caused by the “Volume In Pocket” feature.
Follow the steps below to fix this issue
1. Settings -> My Device and tap on CALL.
2. Scroll down to Increase Volume In Pocket.
3. Deselect it.