This is likely due to GCP Tags used instead of Labels which are the AWS and Azure equivalent of "tags".
Google Terminology:
Google terminology uses both terms of Label and Tag.
Tags are intended to enable a user to configure network setting and are not intended to categorize your infrastructure. Tags are not currently provided in the BigQuery Billing Artifact, which is where CloudHealth receives your cost data. Accordingly, Tags are not available in the OLAP reports, as these are derived from BigQuery.