An easy to use Google Tag Manager plugin for Salesforce Commerce Cloud, specifically SFRA. This plugin is almost entirely plug and play.
gtm_metadata.xml
Note: There is also file named GTM-Container.json in the metadata folder that is a starting template for your GTM container if you need one.
If you are having issues, it's most likely because of some conflict. This plugin extends the Search-UpdateGrid route, extends the base.js decorator of the product model and also a handful of template files. I'd start there. Otherwise feel free to create an issue.