Popup Suddenly Not Appearing Anymore

I’ve had this issue in the past, and it is usually fixed by using an older thankyou.php file that I have saved from an older woocommerce version. However, I cannot pinpoint what’s causing the popup to not appear this time. When I view the page source, the code is there, but the popup is not appearing. I tried disabling all of my plugins that execute script, and my js css minimization plugin, but nothing worked. I seem to have a persistent problem with this plugin seizing to function every month or so, but this time I can’t fix it. Any help would be great.