Right then, I have gone through all the products in my shop, the issue ONLY occurs within one category for ALL products - in the backend the UI appears to totally freeze and not allow editing of anything, if I were to back on the browser I get stuck in a loop and the site frontend also freezes from loading. The only way to use the site in this situation is either initially close down the backend tab (instead of pressing back) and then reopen a new tab to go the admin CP URL again.