I love my fenix 5 plus. I went aqua jogging with it for the first time today. The music cuts out anytime the watch goes below the surface of the water. As soon as it breaks the surface the music starts again. No buttons pressed during any action. Using my water resistant Bluetooth headset. Does anyone know if this is the expected behavior?
For me the bluetooth connection underwater to F5+ works from about 15cm distance.
So I came up with a solution with H2O Audio's STREAM bluetooth mp3 player attaching it to the watch strap and it works just fine while swimming. https://h2oaudio.com/products/stream-mp3-player
I also bought their headphones and used two soft elastic rubber bands from an old backbag through which I put the cord so it is hold on place from two positions.
The upper one is tighter so that that the cord won't move and the cord also goes through the goggles' strap near the earbugs.
It is comfortable, lightweight and doesn't fall off easily and I have used it ever since purchase for listening Spotify while doing pool swimming 
