They are close, but often times not quite. The red lines are perfectly parallel or perpendicular to the horizon line. In photoshop you can hold the shift key while drawing to align them to 90° angles or with the line tool to 45° angles. It's subtle, but it will often times have this "something looks off but I don't really know why"-effect.
The additional box I've drawn is what I mean with rotated. It's still a box in one-point-perspective, but rotated by about 40°. For example your box 3 looks like it is rotated counter clockwise by a tiny amount. Turning boxes this way is fine, but it didn't look intentional in your drawing so I thought I'd mention it.
Also, keep in mind that it's a bit nitpicky, because overall your boxes are good. But it's something that's easy to get rid of once you notice it and has quite a lot of impact in making a scene look believable.
