I used “Meta Pixel Helper” and “The event manager of Meta Business Suite” to check whether the FB pixel event can be triggered properly.
I find that when I add product to the shopping cart on collection page, the “Add To Cart” event could be triggered properly ; but when I add product to the shopping cart on product page, the “Add To Cart” event will be triggered twice.
Looking further at the data in the “Add To Cart” event, the “Add To Cart” event will be transmitted from the pixel code and conversion API, so it is necessary to set up a deduplication, otherwise the event will be triggered repeatedly.
It is estimated that this is the reason for the current problem.
You can find the information on this link:
https://developers.facebook.com/docs/marketing-api/conversions-api/deduplicate-pixel-and-server-events?locale=en_US