iPhone volume lowers by itself

Same here on my xr

The reason for this can be attributed to the "Attention Aware Features" on the iPhone. When this feature is enabled, the device uses its front-facing camera and sensors to detect whether you are actively looking at the screen. If the iPhone determines that you are actively using or looking at the device, it will lower the volume of incoming calls or alerts to avoid unnecessary disturbance.

To disable this feature and ensure that the "Ringer and Alerts" volume remains consistent regardless of whether you are actively using the device or not, follow these steps:

1. Open the Settings app on your iPhone.
2. Scroll down and select "Face ID & Passcode" or "Touch ID & Passcode," depending on your iPhone model and settings.
3. Enter your device passcode to proceed.
4. Look for the "Attention Aware Features" option and toggle it off.

Once you disable the "Attention Aware Features," the "Ringer and Alerts" volume should no longer change automatically based on whether you are looking at your iPhone or not, and it will be controlled solely by the physical volume buttons on the side of the device.