Hi Ph656pwh,
Thanks for reaching out to Apple Support Communities. It sounds like you're having an issue with the Heart Rate app. We're happy to provide some information to assist.
We also recommend you make sure you are on the latest version of iOS and watchOS supported by your devices.
Update your iPhone, iPad, or iPod touch
Update your Apple Watch
For additional help we recommend checking out the article here: Monitor your heart rate with Apple Watch
Specifically the section in grey that mentions "Some anomalies may appear in the displayed data, resulting in occasional heart rate measurements that are abnormally high or low."
If needed, continue with the steps below for optimizing and ensuring you have a great fit for your Apple Watch.
Get the most accurate measurements using your Apple Watch
Wearing your Apple Watch
Cheers!