I am using authorize.net payment gateway and in the last few weeks, I have noticed the number of transactions decline is increasing. Some of our regular customers have to attempt multiple times to make the payment even if they are using the same card.
I have discussed this issue with the authorize.net team and they want the below details.
"we're going to need something from your web server called a Response String. That string would be sent back from us to your website no matter what, as long as some kind of attempt reaches our system, and it will contain the specific error code identifying the problem. We're not able to walk you through retrieving it so you may need to reach out to Shopify for help with retrieving that. If no string is found, it means there's something going on with your site that's preventing transactions from reaching us."