A hire I expected to see isn't showing up.
Check the date range — it filters by hire date, not by when the candidate was added. Also confirm the candidate is still currently in a Hired stage; if they were moved out after being hired, they drop out of the report.
I'm seeing an NA bar.
This means the Job Role used for grouping has no user assigned on that job. Switch Group By to a different dimension, like Lead Owner, to see the same hires resolve to a named group.
The average looks unrealistically high.
A small number of hires with unusually long pipeline stays can distort a group's average significantly. Switch to the Table view and check the hire count next to the average — a group with 1–2 hires is far more sensitive to outliers than one with 20+.