Companion app Drains Apple Watch battery

I’ve just started using Zwift and have paired my Apple Watch through the companion app so I can use Apple TV. It almost never records heart rate and after use the app on the watch stays active and accelerates the draining of the battery.
Is there a fix for this?

I am experiencing exactly the same problem. The green lights on the back of the watch are lit up when I take the watch off. I have another question, I have both Zwift app and Companion app installed on my Apple Watch. They appear to have the same functionality. Do I need both?