Weird cockpit decal white outline

Hi all,
I am developing a modern aircraft and have an issue with the cockpit decals. I followed the descriptions in SDK but still saw the weird white outlines. Could you help me understand which step I did wrong?

Steps:

  1. Make a decal texture using Photoshop.
  2. Export the texture to a tiff image. (no compression, save the alpha channel, discard the layers)
  3. Import the tiff texture in 3dmax and apply to the decal objects.
  4. Export the model to model folder and texture folders. (the textures are exported as png files)
  5. Build the project in msfs2020.

I recommend using SuperPNG to export your png files. Specially when you need the colors to be retained under a transparent alpha layer