Before, when I created a circle and typed “18” for radius, I got a circle with a radius of 18. Now, I’m getting a smaller radius. I don’t know why. I’ve tried this a bunch of times and gotten the same results. The keyboard is inputting 18 inches and SketchUp is not creating an 18" circle.
I’m attaching my file so you can see what happened.
I just opened your model - and I see your smaller circle.
If I start a circle and type 18, I get an 18" radius without issue.
You can also select the circle, and change the radius in the Entity info box.
Hopefully, someone else can chime in if they see any issues.