I have some weird shadows on my objects. More specific it changes when the angle of view has changed. You can see in the first image the middle cushion is lightened and in the second image is darkened. In the middle view is the same as the others but the problem appears on the sides of the couch. I had checked already the normals (face orientation), double vertices, double faces, I don't have any modifier, smooth shading in the entire object is on, the material is simple as you can see in the fourth image, I have turned off the ambient occlusion, the size is close to normal size of a couch, I have only a point lamp (power 1000w size 1m). In the last image, you can see the appearance of the object in edit mode in render view. I have windows 10 64 - blender 2.82 I can't get what it causes this issue. [2 Thanks in advance
Wrong color space for the normal map
First of all you have some object with the normal pointing inside the surface, you can enable the Face Orientation overlay to spot them. I suggest to fix them by recalculating the normals.
Your node setup would be correct if you were using a common Normal Map you can find around the web. Your normal map has been baked with different settings, as you can easily spot by comparing the shades of blue between yours (on the left) and another normal map made from a professionist.
Your is simply baked in another color space. You should ask the person who did it which one exactly is, but if you switch to sRGB instead of Non-Color, all seems fine, so we can assume sRGB is the one.
Here's some normal map from the web: your nuance is clearly lighter.
Change this parameter.
It cant be corrected in blender as far as I know . I guess the textures was created in substance painter . So you gotta unwrap your mesh properly and redo it in substance painter (if i am right)