The watch app no longer runs simultaneously with the apple watch workout app. – Heart Graph Review

the watch app no longer runs simultaneously with the apple watch workout app. If you start the watch heart graph app then the apple watch workout app, the heart graph watch app will still crash: “an error with the workout session occurred: another session is starting.” Another session never starts on its own. Now, if you start the apple watch workout app then the watch heart graph app, the apple workout app will stop without recording its session. PREVIOUSLY, if the heart graph app was started AFTER the apple workout app, both apps would run simultaneously.
Review by Runw/Link on Heart Graph.