I was watching youtube video where poster suggested a trick to control music volume by rotating crown on apple watch by running music app on watch in background and controlling vol by crown when aple watch scree is off I have tried this but every time display goes black rotating crown doesnt work. Im just wondering if this working for you ??? or any idea suggestion you can give Im sure this used to work before on my apple watch but after updating 3.1.3 its not working for me