Depending on how tags are applied, a node does not collect its own resources.
Setting the tag metaparameter in a resource default results in none of the test nodes collecting this resource.
When the tag function is used, then each node collects the other nodes resources, but not it's own.
When the resource has a tag => metaparameter applied directly, then all resources are collected.
However, even when the tag is given as a string rather than an array, the resource is collected ( at least on some resource types, notify, setting the tag as a string did not fully work for a concat resource )
For code samples that will reproduce the behavior, please refer to:
I've also created a table that summarizes the notify resource test results, it is attached to the ticket.