Layout Dimensions Problem

These dimensions are obviously not the same as each other. The horizontal dimension is reading the true distance between the endpoints and not the horizontal projection. Any ideas?

Yes. Both are measuring the inclined length but they are showing it to you in different ways.

It worked as expected for me:

Crappy screenshot, I always set my display resolution to Low.
Are you still using SketchUp 2018? I no longer have that installed.

Drawing convention says its not supposted to be like that, its supposed to be like this

Dimension in Layout has many artistic qualities, I especially fancy the rotate dimension function, and the move to random place functionality.

Thanks I figured out the problem I was not picking and clicking correctly