Health app not recording heart beat after update
I am using a Polar H10 heart monitor connecting to my iPhone 7. After updating to iOS 11 it is not recording my heart rate anymore. Bluetooth discovers the device and the phone can pair it. But the health app does not record the heart rate. When I connect the heart rate monitor to my iPhone on iOS 10 the health app is still recording my heart rate as it has done with the iPhone 7 before the update. Hence the H10 seems to work fine. Also after installing the Heart Beat app by Polar the app can record the heart rate and store it in the health app on the iPhone 7. So, also the iPhone 7 seems to work fine. But the health app still does not record the heart rate on its own as it has done before the update. And using the Heart Beat app is not an option as I am using a different app form my workout and have no interest in switching to the new app (or have them both running). Especially if it worked before. Anybody else experienced similar issues after the update to iOS 11?
Thanks