Dear @J, Ravi Kumar (Cognizant),
Thank you for posting your question in the Microsoft Q&A forum.
Please understand that our forum is a public platform, and we will modify your question to cover your organization domain name in the description. Please notice to hide these personal or organization information next time you post error or some information to protect personal data. Based on your description, you are facing 2 issues while your POC using Microsoft Syntex Content Assembly: Why does the Condition section fail to save selected fields (showing an error icon and resetting values)? and why can’t Microsoft Syntex be restricted to a specific SharePoint site when enabled at the tenant level.
Regarding the Condition section issue, this may be conditional fields fail to persist and reset automatically with an error indicator. This occurs within the modern template editor and is not caused by permissions, licensing, or field configuration on the customer side. It would be helpful if you could share your screenshot about this issue so I can better understand and find helpful information for this situation.
For reference SharePoint Syntex service description
In case you need this to be resolved as soon as possible. I recommend opening a Microsoft Support ticket under SharePoint / Microsoft Syntex to report the issue and track progress. And if you are IT/global admin of your organization. You can contact to Microsoft Support team via the link: Get support - Microsoft 365 admin.
Or you can submit support ticket via Ticket Support portal: In the Microsoft 365 Admin Center > Support > Help & Support. You can raise support ticket: https://admin.microsoft.com/#/support/requests
And if you're unsure who your Global Admin is, this guide may help How do I find my Microsoft 365 admin? - Microsoft Support
Regarding restricting Syntex usage to specific sites Microsoft Syntex is designed as a tenant-level service. Once enabled, it is available across all SharePoint sites in the tenant by design. There is currently no supported capability to enable or disable Syntex on a per-site basis. Access control can only be managed indirectly through licensing assignments and SharePoint permissions.
For more detailed information SharePoint Syntex service description
If site-level control is required, I recommend submitting feedback through Microsoft’s official feedback channels via feedback forum link Ideas · Community
The product team is in charge of the site, and they constantly check customer reviews and feedback, The higher votes, the more attention the related team will pay on. And a lot of the features are developed and improved based on customer feedback.
I hope information above could meet your expectation, if you have any other questions, please feel free to reach out.