Hoping if anyone has any advice. I've found that when sharing Zendesk Guide article links in Slack, irrespective of the brand or company, links will not unfurl / preview in Slack. EXCEPT for Zendesk's own Help Centre. 

Exploring the data in the head of the document doesn't show any extra data within Zendesks own Help Centre, so I'm a little lost as to why article links do no unfurl: 

Desired outcome: 
Example of other help centres links not unfurling (despite them all having Title, description and icon links in the document head): 


These links were all posted individually btw, I'm aware that Slack has it's own rules as to when it unfurls. But through testing, it appears Zendesks own HC works perfect every time, and any other Zendesk Guide based HC will not work.