Hi there devanshs004,
Welcome to Apple Support Communities. We understand you are asking about how your iPhone and Health app track activity data. We have some steps that should help. We'll be working from this article: Manage Health data on your iPhone, iPod touch, or Apple Watch - Apple Support
How Health handles data from multiple sources
The Health app takes similar data from different sources, like steps recorded from your iPhone and activity from your Apple Watch, and organizes it based on where it comes from. By default, Health prioritizes data in this order:
1. Health data that you enter manually.
2. Data from your iPhone, iPod touch, and Apple Watch.
3. Data from apps and Bluetooth devices.
When you add a new data source, it appears above all other apps and devices that contribute data in Health. You can change the order of sources at any time.
You can change the priority of which source you want your activity (steps) data to come from.
- Open the Health app, then tap Browse at the bottom of the screen.
- Tap Activity > Steps.
- Scroll down, then tap Data Sources & Access.
- Tap Edit.
- Touch and hold the Change Order button (top right of display) next to a data source, then drag it up or down in the list.
- To turn off a data source so that it doesn't contribute any more data for that category, tap the checkmark next to the source.
- Tap Done.
Note: If multiple sources contribute the same data type, then the data source at the top will take priority over other sources. Any new apps or devices that you add go to the top of the list automatically, above your iPhone.
Feel free to reply back with any questions while working through this.
All the best.