I'm facing this issue the app I'm working on, everything works fine besides this little weird behavior.
When I run the completion on my intent handler with any failure, custom or not, Siri repeats the error twice and then finishes with "Done" or "That's done" or "Ok".
I checked if the completion was being called multiple times but that was not the case. Then I downloaded the Soup Chef example app, provided by apple, and changed the handler just to immediately run the completion with the .failureOutOfStock error and observed a similar behavior.
I would post the short video I made or link to it here but it seems I'm not able to do so. If anyone wants to see I uploaded it on Streamable, /f73ujr.
This was building on Xcode 12.5.1, running on an iOS 14.6 device.
I didn't find anything about this behavior anywhere, does anyone know anything about it?