Facebook Conversion API event is less than the Pixel

[Hridoy]

We have a WooCommerce store and use the GTM4WP plugin for the Data Layer purpose. GTM Base code is connected through the WP Code plugin.

The Meta Pixel and Conversion API are done properly through GTM (Web + Server). I am using a custom domain and custom loader as well.

The issue is that the Browser event is always higher than the Server events, especially for the Page View event. We hardly see the Server event higher in Event Manager for Page View.

Other events like ViewCategory, View Content, and ATC are working well. There is either the Server event overlaps with the browser or remains the same.

The less server events are also seen in Begin Checkout and Purchase sometimes. Is there anything that blocks the Facebook Conversion API and doesn’t work sometimes?

I have used both FB CAPI tags from Facebook Incubator and Stape.io. But the issue isn’t resolving.

Note: Our triggering is the same for Pixel and CAPI tags. No other pixel integration is there. The same kind of setup is working well in Shopify.

[Alex]

With page view I think it’s simple, usually more web events are due to the fact that page view is automatically sent when the url is changed as it considers it a history change event. And url change (adding query) can happen for example when user switches product type (colour, type, etc.).
Make sure you have this checkbox enabled on FB page view tag:

With other events - you may have e.g. payload issues that cause the server event not to be accepted. For example, if purhcase event has currency, but no value in some cases - such event will not be accepted by Meta.
To make sure that there are no such cases - enable logging in FB tags on the server and see if there any not 200 response.

Troubleshooting server-side tagging using server GTM logs