I thought it was delay in Purchase first my app trigger Purchase event after thank you page took 5 seconds now we improve more code and it now take 2-3secs.
but shopify store + FB event Manager have different stats i want to know how to improve more code to get exact Purchase event tracking
Why was it taking up to 5 seconds to send a purchase event?
Is your pixel compliant with the new CCPA? (Unlikely to affect the accuracy, but I'd highly encourage that for any pixel app to get on-board.)
On a similar note, it's possible browser privacy settings and extensions are limiting what you're tracking. You can look at your traffic in Google Analytics to see Safari 13* purchasers over the time period.
Basic but often overlooked factors to consider is the timeline. We exact dates are you looking at in Shopify and Facebook? And secondly, data is not retroactive so any changes you make to the pixel means the dates you analyze are from then onward. Advanced