Using different web containers on same domain

Basically my user journey is main domain website example.com then when clicks registers goes to the crm which is my.example.com

So for this we use 2 different web containers one for the website and one for the crm site.

Now after doing all the code changed and pointing on the custom domain the gtm code on the main site doesnt load at all, but when going to crm the other gtm code loads.

Any help is appreciated.

It’s hard to help here without looking at the site and how you have GTM installed.

You can check the browser console for errors and check if you are using the correct GTM loader on the main site.