Galaxy S6 :: Music Changing To Speakers Upon Sending A Text?

If I am listening to music and send a text it will stop the music for a second or so, then start playback up through the speakers then switch back to the headphones.

Now if I am having a conversation with someone via text this is quite irritating as sat on the bus and every so often my phone just plays music quite loud for a second before going silent.

I use poweramp and have tried the audio focus options there but I never had this issue on my older s4 with poweramp also. I am having to resort to just not listening to music at all.