[Vuejs]-VUE 3 not rendering template defined in the custom component, no errors in the console

Configuring the compileroptions with isCustomComponent blocks execution of the component.
I think it’s a definition for tags that are used outside of Vue and should be ignored during execution.

The following explanation is taken from the documentation.

If we want to add a custom element defined outside of Vue (e.g. using the Web Components API), we need to ‘instruct’ Vue to treat it as a custom element.

Unfortunately, I’m not an expert on Vue.