Meta Pixel/Conversion API Expert Needed

We're seeking a Meta Pixel/Conversion API expert to resolve a purchase tracking discrepancy between Meta Ads and Shopify. The task involves auditing our implementation to identify the cause of the discrepancy, checking for duplicate Purchase events, and verifying event firing throughout the purchase flow. The expert should have extensive experience with Meta Pixel, Conversion API, and Shopify, and be able to explain the issue and solution clearly. Please include your approach to diagnosing the problem and your estimated timeline to fix it.