The ruler in Dimension is not proportional to itself

I am in the middle of my first 3D rendering project for a fancy house under construction, using Adobe Dimension and "inches" as my unit of measurement for the app's ruler. (I have switched between my windows laptop and my partners macbook air using the cloud file storage.) It is not until now that I am coming full circle around the perimeter of the building, knitting it all together, when I've realized that the dimensions taken directly and specifically from the blueprint do not add up within the Dimension UI, leaving gaps at the back of the house between where the last 2 walls should meet, among other proportion issues now rearing their heads such as posts a set distance away from the patio doors not adding up. Even summing up the total length of the wall faces on 2 different directional sides of the building (there are various points where rooms poke out and/or recess from the next/last room behind them) and creating an object of that length doesnt line up with the edges of the building.

I really hope what I'm saying makes sense. I am truly at a loss on what to do aside from fudging everything so it looks kind of OK and hope that it's acceptable. I am super confused as to how this could happen. I understand that "inches" is not an electronic measurement, but please, if anyone can help me fix this problem, I would really appreciate it. For a side of the building to go from 711 inches total on the plans to being about 660 inches in Dimension, despite each wall's length figure adds up to 711, is really confusing.

Thanks for reading.