Challenge
I am unable to use embedded link or SmartLink for Smartsheet in Confluence pages / live docs.
Background
Hello and welcome to the Community @NH
Smartsheet is supported by Atlassian Smart Links, and the authentication is user-based, not space-based. Some Smartsheet URL types not supporting embed view, and unsupported or permission-restricted URLs can not unfurl at all.
Check three things first:
Since it worked for you in other spaces before, paste a simple published Smartsheet link into a new page as a quick test. If that still fails, raise it with Atlassian Support.
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