Inventory Widget: "We cannot complete the request" when submitting

Trying to get this form to work:

I've searched and done what's been recommended... I've:

1. Cloned the sheet

2. Deleted/re-added the inventory fields

And I must be doing something wrong, but I can't seem to find it.

I reset your API limit and cleared the cache of your form, that should fix it. Can you please check and confirm if the issue persists on your end?

Related Guide: 

- How-to-Clear-Your-Form-Cache

- Daily-API-Call-Limits