Average position shows up in almost every SEO report, and hardly anyone can explain what it means. It's an average across every query a page appeared for, weighted by impressions. A page that ranks 1st for a branded query and 40th for thousands of generic ones can land around 12, which tells you nothing useful. It also drifts when Google adds new queries or tests a new layout, even if your rankings haven't moved at all.
I'd stop using it as a headline KPI. Report clicks and impressions by query group or by page instead. If you want a position signal, track a fixed set of 20 to 30 target keywords with a rank tracker that checks the same SERP on the same schedule. An average can show a rough direction, but it's a poor basis for a call like "the SEO work isn't working." Does anyone still put it in client reports, and how do you explain it?