Hi @Heimann, Justin,
Thank you for posting your question in the Microsoft Q&A forum.
Based on your sharing, the behavior that the manual formula works but the Script doesn't indicates that the issue is related to the way the script handles the external reference. There are two possible reasons for this situation:
- External workbook issue: When a VBA Macro or an Office Script uses a formula referencing an external workbook, the formula usually needs the source workbook to be open at the moment.
- Formula syntax in the script
If possible, can you share us the script code you're using and also the formula that works when adding manually so I can take a look to clearly understand the situation and provide the most appropriate solution for your concern.
Please understand that our initial response does not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.
Thank you for your understanding and cooperation. I'm looking forward to your reply.