We're running 2.3.8.
Here's a screenshot of the Categories and Items Full View.
Nothing out of the ordinary that I can see. The bracketed 46 threw me off at first, but when you look at the scale used (see screenshot in response to Emma's post), the 0-30 with .5 increments scale only starts using the half point increments above a score of 15. So, the 46 appears to represent the number of increments in the scale itself (it's not clear to me why this is important or useful info to show in the grader report, but there you have it).
As far as the course category settings are concerned, I'm not entirely sure where you are suggesting I look. Here's a screenshot of the course category settings page for that category that I'm aware of, but it doesn't have any settings that impact the GB, so I'm guessing you're referring to something else.
Thanks for helping me to troubleshoot this issue.