When using the Now Mobile app on iOS v13.x, clicking "Add to Cart" fast and multiple times on a hardware item shows the "Unique key violation…" error on top of the page.
This issue does not occurs on iOS v12 where the "Add to cart" button is not visible:
1 - Open the Mobile Requestor app.
2 - Navigate to Services > Hardware > Mobiles > iPhone 6s.
3 - Keep clicking on "Add to Cart" fast and repeated times.
Observe the message "Unique key violation…" displaying on top of the page.
This problem is under review and targeted to be fixed in a future release. To receive notifications when more information becomes available, subscribe to this Known Error article by clicking the Subscribe button at the top right of this form.