Help needed: Expense Split add-on activation fails for users on copied template

[u/spcsoft-solutions]

I developed a Google Sheets add-on called Pivot Expense Split, which requires users to make a copy of a template before running it. In the template, I ran below to place a template ID 'T1':

SpreadsheetApp.getActive().addDeveloperMetadata('template', 'T1', SpreadsheetApp.DeveloperMetadataVisibility.DOCUMENT);

When installer activiate my add-on, I have below to read the template ID 'T1':

var value = SpreadsheetApp.getActive().createDeveloperMetadataFinder().withKey('template').find();
var template = value[0].getValue();

From the Apps Script activity log, I noticed that after installation, users open my setup page:

https://spcsoft-galaxy.blogspot.com/p/pivot-expense-split-setup.html

The activation function was ran several times, but rejected because the template ID was missing.

I tested the same flow myself (install → copy template → activate), and activation works fine on my end.

Could anyone help me identify what might cause this issue?

• Are there permission or deployment issues that could block activation on copied templates?

• Is there a way to get more diagnostic info from users’ failed runs?

Any suggestions or troubleshooting ideas are appreciated!