Casting to TV: volume too loud

Whenever I cast Plus content from Chrome browser on my Android phone to my TV the volume automatically goes up to a 100 on my TV... 🙉 Nothing is as frightening as Daniel shouting "Welcome to Fitness Blender" at top volume. I guess at least I'm making sure all my neighbours are awake too. 🤷🏻‍♀️ Bet they're pleased (!)

What am I doing wrong?