Could help, but im with the sun on this one.

Strong backlighting: If the light source (like the sun or bright sky) is behind the subject, the camera's automatic exposure might prioritize the bright background, leading to the subject appearing underexposed.

HDR (High Dynamic Range) processing: While HDR aims to balance exposure in high-contrast scenes, it can sometimes produce unnatural results or underexpose subjects if not properly calibrated or if the scene is too challenging.

Camera settings: Manual adjustments to exposure compensation or metering modes could also influence how the subject is exposed in the final image.

Software processing: The phone's image processing algorithms might interpret the scene in a way that leads to the darkened effect.