Box2D collisions error

I am currently using box2d physics engine in java in libgx, and i am facing problems with collisions. The problem is that the body stops moving, and a collision point appears while on a flat area. The way im working is i am making multiple bodies, each representing a block, and those blocks are side-by-side. Look at the collision point here:

the body should not collide here for the Y coordinate of the bodies is equal, and their side is equal as well.

float PPM = 100;
float side = 45;
     for (float i = start; i < end; i++) {
        /**
         * perlin noise for terrain
         */
        def.type = BodyDef.BodyType.StaticBody;
        float place = Maths.map(noise.noise(off, off), 0, 1, -10, 50);
        if (place < 10) {
            place = 0;
        } else if (place < 20) {
            place = side;
        } else if (place < 30) {
            place = side * 2;
        } else if (place < 40) {
            place = side * 3;
        } else if (place <= 50) {
            place =  side * 4;
        }


        place += side / 2;

        float posx = (i * side);
        float posy = place;
        float size = side / 2f;
        def.position.set(posx / PPM, posy / PPM);
        b = world.createBody(def);
        shape.setAsBox(size / PPM, size / PPM);
        fdef.shape = shape;
        fdef.isSensor = false;
        b.createFixture(fdef);
        off += 0.01;
        toSetLast = posx + side;

        GrassBlock grass = new GrassBlock(b, new 
        Vector2(b.getPosition().x * PPM, b.getPosition().y * PPM));
        //dirt under grass
        for (float j = (place / side) - 1; j >= -1; j--) {
            posy = j * side;

            def.position.set(posx / PPM, posy / PPM);
            b = world.createBody(def);
            shape.setAsBox(size / PPM, size / PPM);
            fdef.isSensor = false;
            fdef.shape = shape;
            b.createFixture(fdef);
            DirtBlock dirt = new DirtBlock(b, new 
            Vector2(b.getPosition().x * PPM, b.getPosition().y * PPM));
            addBlock(dirt.getLocation(), dirt);
        }
        addBlock(grass.getLocation(), grass);

    }