Hey all, hoping someone has hit this and knows the fix.
Setup:
- Shopify store using the native Facebook & Instagram channel app
- Data sharing set to "Maximum" (Pixel + Advanced Matching + Conversions API)
- ~290 events/day, mostly anonymous traffic from Meta Ads
- Both browser pixel and CAPI are firing — Meta confirms 87% of pixel events are also being received via Conversions API
The problem:
Event Match Quality on PageView and ViewContent is stuck at 6.2/10. The smoking gun is in the Event Deduplication tab in Meta Events Manager — Total Event Coverage Rate is only 43.97% (Meta's threshold is ≥75%).
I exported the "Sample for debugging" CSV from Meta and found something wild:
Out of 73 sampled events from the past 7 days:
- 38 rows = only browser fired this event_id (1, 0)
- 33 rows = only server fired this event_id (0, 1)
- 1 row = partial match (2, 1)
- Zero rows = clean (1, 1) match between browser and server
All event_ids start with sh- (Shopify-generated prefix), but the actual values are completely independent between the Web Pixel and the CAPI source. So Meta sees what should be ~36 deduplicated pageviews as 73 separate events.
Sample of browser-only event_ids:
sh-e250ee85-B2EC-48C2-5C67-9F79DC6CDC56
sh-ddea77f7-6E1C-4EE2-509A-36CFABF9C6A8
sh-de44f128-2F9D-47E8-C687-3762FEE74DB8
Sample of server-only event_ids (totally different values):
sh-df47ba76-4D4D-4368-CB2D-7059B4450AD3
sh-ddafe590-FEC6-4463-3533-16020E836622
sh-defee737-EEF1-4975-0879-BB975709DA27
Bonus weirdness: two rows in the export have a totally different prefix pcm_plugin-set_[long hash] that I cannot trace to any installed app or theme code. No idea where they're coming from.
What I've already ruled out:
- Theme is 100% Pixel-free (no
fbevents.js, nofbq()calls, no Pixel ID strings in.liquid/.js/.json) - Only one Meta Pixel installation in Settings → Customer events (Facebook & Instagram, "Connected", method "Server + Web"). No duplicate Meta-related custom pixels.
- Settings → Apps and sales channels: no duplicate Facebook/Meta/CAPI apps
- Online Store → Preferences → Facebook Pixel: legacy field is empty
- Automatic Advanced Matching enabled with all fields toggled on
- Test Events tab confirms browser pixel is firing correctly (the native app doesn't pass
test_event_codeto server events, so server events don't show up in test mode — known Shopify limitation, not the cause)
What I'm asking:
- Has anyone else hit this with the native Shopify Facebook & Instagram app? Is this a known bug?
- Has anyone successfully gotten Shopify support to fix it, or did you eventually migrate to a third-party CAPI tool?
- If you migrated — what did you switch to (Aimerce / Stape / Elevar / Trackify / something else) and did the dedup actually resolve?
- Any idea what
pcm_plugin-set_could be? Could it be from a previously uninstalled app leaving behind a script? - Is there a way to force the Facebook & Instagram app to use a deterministic event_id (e.g., based on session + URL + timestamp) on both browser and server?
Filing a support ticket with Shopify in parallel but figured the community might respond faster than tier-1 support. Happy to share the full CSV or screenshots if it helps.
Thanks for any pointers.