Hi,
Please provide screenshots in English. It's hard for us to check what setting is which if it's not in English.
If you don't see the payment notifications in your apache access log, then you can rule out a lot of things. It can't be a menu item issue, or a charset issue, etc.
Normally, I would say that either the "allow notification" setting was turned off (so PayPal doesn't send the notifications), or the "enable validation mode" of the plugin was turned on (so that the payments need to be manually validated in the PayPal merchant account).
Looking at your screenshot, both options are correctly configured. So you shoudl check the settings of the merchant account on the PayPal sandbox website. Check that the payments are validated there, and check the IPN history area of the account. There, it will say what problem it had with the notifications. And if you don't see the notifications there, then check the settings of the account to make sure that the notifications are activated and the validation mode turned off.