Fix Delayed Tracking on Shopify Store

I run a Shopify ecommerce store and currently have Google Tag Manager and Stape server-side tracking installed for Meta Ads Conversion API.

However, my tracking is delayed and inconsistent.
Purchases appear in Shopify immediately but Meta receives them much later.

This affects optimization and scaling performance.
I need an EXPERIENCED tracking engineer (not an ads manager) to audit and fix my setup.

Current setup:

Shopify -> DataLayer -> GTM Web -> GTM Server (Stape) -> Meta Conversion API

Issues:

Delayed purchase events in Meta
Possible poor event deduplication
Weak event match quality
Scaling instability due to signal quality

What I need fixed:

Correct purchase event firing timing
Proper browser and server event deduplication
Improve Event Match Quality
Verify domain and AEM setup
Ensure first-party tracking reliability (iOS compliant)
Clean dataLayer parameters
Ensure Meta receives real-time optimized signals

Important:

This is NOT an ads campaign job.
I need a tracking/analytics implementation specialist.

You must have:

Shopify tracking experience
GTM server container experience
Stape experience
Meta Conversion API experience

Please describe how you would audit and fix the setup before I hire.