In many games, especially those involving collection and avoidance mechanics, developers craft the environment to challenge players or to guide them towards making split-second decisions. Here's what might be happening:

1. Hitbox Size and Shape: The hitboxes, which determine the area around an object that can interact with other objects (like your character’s collector), might be different between the coins and the stones. Stones might have larger or more favorably shaped hitboxes, making them easier to pick up accidentally.

2. Object Placement and Trajectory: The placement of stones and coins might be strategically done to create a challenge. If stones appear more frequently or in the path of typical movement, you'll end up collecting them more often.

3. Game Physics: Some games use physics that can unexpectedly affect how objects are collected. If heavier objects like stones have physics properties that make them gravitate towards your collector more than lighter objects like coins, this could explain your experience.

4. Player Perception and Reaction Time: Sometimes, it’s not just the game design, but also how players perceive and react to fast-paced elements. Stones might be more noticeable or seem more valuable in the heat of the moment.

Developer Intentions and Game Balance

Developers often design games with specific challenges in mind. In your case, the frequent collection of stones over coins could be an intentional design to increase the game's difficulty or to encourage players to change their strategies and improve their skills.

Gathering Feedback and Improvements

If many players experience similar issues and it affects game enjoyment, developers might need to consider adjustments. Feedback through forums, reviews, and direct communication can highlight these issues, leading to patches or updates that balance the gameplay.

Conclusion

Your experience with automatically picking stones may not just be a coincidence but a part of the game’s challenge. Understanding these elements can enhance your strategy and potentially improve your gaming experience. If it becomes too much of an issue, reaching out to the game developers with constructive feedback might lead to a better balanced gameplay for everyone.