Using ArcGIS Pro version 2.7* updated from 2.6.0 (which did not solve this issue)
I built my own network based on street center-lines data. I'm not concerned with looking at vehicular speeds or direction along the network at this point so I'm using length as my 'cost'.
I input the facilities and set the distance to feet, established the breaks at 150, 300, 450, and 600 ft. Looking at the generated polygons critically I'm seeing some issues. The red line in this picture is measured out to 150 ft but the polygon is far larger than what I would expect.
What could be the issue I am overlooking here?