Black Lines Overlapping

Hello,

I'm not sure what is causing this issue, but I have overlapping black lines on my shapes. It appears that there are black borders around every shape in addition to the stroke. I'm using a 2pt black stroke, but regardless of the stroke size and color (or even if I remove the stroke) there is a black border surrounding each shape. What's worse is this black border does not care about the arrangement of the image.

In the above image, the lighter brown squares are on top of the darker brown squares. I do not want the lines overlapping. The black line intersecting the bottom of the light brown squares should not be visible because the dark brown squares are underneath (or behind) the light brown squares.

These squares do have a 2pt black stroke, however, what you are seeing is not the stroke; when I remove, resize, or recolor the stroke those black lines remain unaffected.

I am using Adobe Illustrator 22.0.1.