Topic on Talk:Talk pages project/Replying/Flow

It does work if "(UTC)" is added to the template.

The tool does not produce a "reply" button for comments which have the "undated" template — where the original poster signed with ~~~, producing a signature without a timestamp, and another user substituted a template like w:en:Template:Undated.

It should work, but the "undated" template must include the time and timezone (and the entire timestamp must be in the usual format).

If you see a page where that is the case, but the "reply" button is missing, can you post a link?

I demonstrated in my sandbox (permalink). The template does not add the "(UTC)". Do you think this is the problem?

Yes, it'll work with the "(UTC)" added.