Thank you for your support of our product. 

The halo around the display area is a normal phenomenon. When the projector is used for side projection, the entire image is skewed, with one side larger than the other. To provide you with a better viewing experience, the automatic keystone correction adjusts the image into a rectangular shape. However, the original skewed area remains part of the projector's normal display area, resulting in some halo being visible in that region.

We apologize for any inconvenience this may cause and appreciate your understanding.

If the above solutions cannot solve your issue, please contact Nebula Customer Support at support@seenebula.com for further assistance.