FBX and DAE files from Blender have transparent shader

Hi,

When i import an asset from Blender saved in FBX or DAE, the material rendering mode is always set to transparent instead of opaque. It's easy to change it but it's annoying to have to fix this each time I add a new asset. Is there an option i have missed in Blender or a setting to change in Unity? It's more likely and Unity bug.