Why are QR Code scans counted twice?

If your mobile device scanning the QR Code is requesting the URL in the QR Code twice, there is a good change, that your QR Code Reader App requests the link twice for the following reasons.

The first time the URL is requested to create a preview of the target URL or to do a safety check to see if the target URL is not leading to a phishing page or to malicious content.

The second time the vanity URL in the QR Code is requested, the actual forwarding to the target URL is executed. This explains the double scan.