Great for testing - but a bug?
Checked it with the barcode generated by telepen.co.uk and it has the same issue.

This utility app allows users to scan Telepen format barcodes. It supports both numeric and alphanumeric barcode data, providing a straightforward solution for reading this specific barcode type.
1.5.1
December 12, 2018
Improved support for additional barcode symbologies
Telepen Scanner is used to scan barcodes specifically in the Telepen format. It can read both numeric and alphanumeric data encoded within these barcodes.
Telepen Scanner supports reading both numeric and alphanumeric data from Telepen format barcodes. This covers a wide range of information that can be encoded.
Yes, Telepen Scanner is available for free. There are no costs associated with downloading or using its core barcode scanning functionality.
Telepen Scanner is designed for Apple devices, including iPhone, iPad, and iPod. It requires iOS to function.
The latest version of Telepen Scanner is 1.5.1, which was released on December 12, 2018. Updates are not frequent, with the last update being several years ago.
Telepen Scanner has an age rating of 4+. This indicates it is suitable for users of all ages, with no mature content.
No, Telepen Scanner does not contain advertisements. As a free utility, it provides an ad-free scanning experience for users.