Why does the Confluence API inconsistently provide SourceTemplate metadata?

[Jason Kim]

Hi Community!  

I would like to utilize a Confluence API to trace back to which Global Template or Global Blueprint a Confluence document was originally derived from. 

When I assess the API response URL, which follows this pattern:

https://acmecorp.atlassian.net/wiki/rest/api/content/12345678?spaceKey=PM&expand=metadata.properties.sourceTemplate

The metadata response will inconsistently come back with either the Global Template or Global Blueprint information that I am looking for. 

Does anyone have any ideas why this information is not consistently provided? 

Are there better APIs that would provide this insight?