Problem exporting AORM (Ambient occlusion, roughness, metallic) textures map in png format

-Windows 11

-3D Sampler 4.0.2

Hi

There seems to be a problem when exporting AORM (Ambient occlusion, roughness, metallic all in one texture) textures map using the unreal engine 4 preset in png format. When I try to export it in png format, the image is all black. But, when I export it in jpg format it works perfectly.

3D Sampler export (Unreal engine 4 preset)

AORM/4K/JPG

AORM/4K/PNG