@mattsuch
It sounds like you followed the correct procedure initially by uploading the KB document and setting it as the KB source in the agent settings. If the KB source has disappeared from the selection options, it could be due to a few reasons such as a system update, a glitch, or the file may have been inadvertently removed or corrupted.
Here's what we can do to troubleshoot the issue:
1. Please check the 'files' tab again to ensure that the KB document is still there and hasn't been deleted or moved.
2. If the file is still there, try re-selecting it as the KB source in the agent settings.
3. If the file is not there, you may need to re-upload it and then set it as the KB source again.
4. Ensure that there are no restrictions or permissions that might be preventing the KB source from being displayed.
If after these steps the problem persists, it might indeed be a bug or a system issue that needs further investigation. In that case, I would recommend reaching out to the technical support team for a more in-depth analysis and resolution.
Would you like to proceed with checking the 'files' tab and attempting to re-select the KB document, or do you need further assistance from the support team?