PHP Shop Data Bug Fix

I run a PHP-based site that lets me manage shop products and a sales list. Right now I can add new items in the back-end, but they never appear properly , and when I try to remove outdated records they simply stay in the database. No visible error messages show up—things look successful, yet nothing actually changes.

I need someone to trace and resolve whatever is blocking

• product and sales data from being inserted or updated
• old entries from being deleted
so that both the admin panel and the live storefront stay perfectly in sync.

Please audit the relevant PHP, MySQL queries, and any front-end caching layers, repair the logic, and test thoroughly. A brief note on what you changed and how to replicate the fix will be the final deliverable.