Prestashop 9 Checkout Fix

Running Prestashop 9.0.2, I’ve hit a snag: when customers reach the final step of checkout the page simply refreshes and the order never completes—no error shown on-screen, just an endless loop.

I already scanned the server logs and noticed a few entries, yet nothing conclusive; the problem still slips past me. I haven’t managed to reproduce any obvious exception with browser dev tools either.

What I need right now is:
• A clear diagnosis of the root cause behind this looping refresh on the last checkout step.
• A working patch or configuration change that lets orders finalize normally.
• A brief note explaining what went wrong and how you fixed it so I can prevent the issue in future updates.

Prestashop core, custom modules, theme overrides, PHP or MySQL mis-configuration—whatever is hiding the culprit, please trace it and get checkout flowing again. Speed matters; the shop is live and every stalled order is a lost sale.