Partially visible textures.

[NapalmTheCommies 1]

Hey, I have been having a problem with some certain recktangles being invisible and others not.
I have not yet found an effective way of fixing these.
I have tried copy and paste the same object and reversed the normals of one of them.
Even with both of then inside each other and one being reversed it did not fix the problem.
You can see trough one side, but on the other side it is visible as it should be.

 

 

This is a schreenshot of one of my objects that are effected.
I have put the object further forward to show the back
The emblem in question is not inside the beret, the invisible parts are visible from the rear.
(Sorry for bad grammar)

Thank you for your time.

EDIT: It has been solved by a kind gentleman on the discord.
          The key was to enable face orientation in blender.