So I've been running into an issue recently with Google Tag Manager (GTM). And I will explain our current app setup and how we are using Google Tag Manager.
1. Custom Front End
Our custom front was developed using Shopify's JS Buy SDK. So it's another app that is just using Shopify's API to gather product / collection data (not a liquid template / Shopify related template). This app's url is "sitename.com" let's say. And when it's time for checkout, we use the url that is attached to the cart we received from the API. Of course this url redirects to the Shopify site's checkout page.
2. Shopify Site
We only use the Shopify site for its checkout page. And to make the page a part of the same domain, we connected the Shopify site to a sub domain "checkout.sitename.com". So whenever we redirect the customer for checkout, it lands on "checkout.sitename.com/xxxx/checkouts/xxxx".
We are using Google Tag Manager setup with an Ads Conversion tag and a Conversion Linker tag to track conversions from purchases. So we put the global GTM tag in our app and the other tag in the body. We also put the global GTM tag and body tag in the Shopify liquid template of the Shopify site. And for safety measures, I also put it in the Google Analytics section of the Shopify store settings. Then in the Shopify Checkout settings, I added a conversion script to fire when a checkout was completed.
The issue at hand is that we are not able to see any conversions that came from our Google Ads despite adding the tracking and sales being made. Our suspicions after talking with Google support is that the conversion loses tracking once it moves from our app to the Shopify site. Mostly due to the Shopify site being on a "checkout." subdomain.
Has anyone faced this? Or does anyone know if it's possible to host the Shopify checkout & a custom app on the same domain without using a subdomain?