28 Feb 2024 · GA4 · medium severity · fix verified 9 Sept 2026
Primary Channel Group — the editable default channel for all channel reports
'We have added the Primary Channel Group, a new, editable channel group that will be the default reporting channel for all channel reports.'
Source: What's new archive — Feb 28, 2024.
What it breaks
Editing the primary group changes every channel report retroactively for the reporting window; two people editing it break each other's comparisons.
Who it hits: Properties with several editors.
The fix
Document the primary group's rules; change it once, annotate, and freeze.
fix artifact · #A-009
Source group and UTM audit checklist
The checks that keep channel reports honest through Google's dimension changes: the Google tag before custom events, one family of traffic-source dimensions per report, Source Group vs raw source, the primary channel group frozen and documented.
- verified_on
- 2026-09-09
- next re-check
- 2026-12-01
- status
- current
Sources linked on every entry · artifacts stamped and re-verified · ← all changes