Changing the survey link would mean setting a workspace URL. If you set a workspace URL in that case the QR code will get changed. If you have set a new workspace URL then please download the new generated QR code. Please log out and log back into the account to view the updated QR code. Help file: https://www.questionpro.com/help/workspace-url.html
The QR codes are in QuestionPro branding (blue, logo, branding under the QR code). Can I also get the QR Code in neutral black without QuestionPro branding?