If your Opening Balance TB was pre-close (P&L accounts still carrying full prior-year activity), the GENUS GL won't match a post-close QB TB until you run the year-end close.
This step posts a single journal dated your fiscal year-end that zeros out every account flagged P&L in accountgroups and rolls the net to your Retained Earnings account. Idempotent — re-run with "replace existing" to redo it.