This article discusses issues related to the heart rate analysis in Pillow.
Make sure you use a wearable device that tracks heart rate
Pillow does not track heart rate directly. It performs heart rate analysis using data from Apple Health that has been provided by a wearable device like the Apple Watch or another compatible device/app.
Confirm that you use the latest version of Pillow
Open the "App Store" app.
Tap on your profile icon at the top right corner of the screen.
Swipe down on that screen to refresh.
Check if there is any available update for Pillow and install it.
Confirm that Pillow has permission to read heart rate data from Apple Health
Open the "Apple Health" app on your iPhone.
Tap on the profile icon at the top right corner of your screen.
Tap on "Apps".
Select Pillow and make sure that the required permissions are switched ON so that Pillow can read the data.
Additional steps
If the above recommendations don't work please restart your device and check if the issue is resolved. Also, please bear in mind that data synchronization between the Apple Watch and the iPhone is not instant so in some cases, it might take a few minutes for the Apple Watch to send the heart rate data to Apple Health.
If you are still experiencing any issues, please contact our support team to help you.