Hey @user072319 ,
Thanks for bringing this up. This is definitely an issue on Shopify’s end, the expected outcome should be that the “Charge was Declined” notification should appear immediately upon the user cancelling the charge request (read here: https://community.shopify.com/c/API-Announcements/Upcoming-Change-Declined-app-charge-redirects-will-now-be/td-p/439398)
I have logged a ticket to the appropriate team to get this resolved