If you experience being tagged through barriers or around corners it is due to bouncing IR light.
All light, whether visible or invisible like IR light will bounce on reflective surfaces. That is the laws of physics and cannot be changed.
IR light is blocked by most materials the same way as visible light. So any material which hides a person from visible light will also hide the person from IR light.
For that reason EVOTAG is designed for outdoor use!
When playing indoors shooting a 100 meter range IR beam may cause it to bounce so many times that it is actually almost impossible to miss a target.