XF 2.2 User Upgrade problem

[Tempritscher]

Greetings,
I've been having a problem with my forum for a while now.
Unfortunately, the user upgrade system via PayPal isn't working properly for me.

After the user has purchased a paid rank, the payment via PayPal goes through, but the user doesn't automatically receive the purchased rank.
I contacted the website host yesterday, and they tried to reproduce the error. Unfortunately, they weren't able to identify the error based on my approach.
The payment log also doesn't show any information about a payment.

Another user said this was due to the PayPal website. I activated the IPN via PayPal and tested two versions of the link. However, the result was always the same.
Example 1: /payment_callback.php
Example 2: /payment_callback.php?_xfProvider=paypal

A few days ago, I completely reinstalled and reconfigured my forum. Until recently, I was using the latest version of Xenforo 2.3.
Since the most recent installation, I've reverted to version 2.2.17 because I was having some compatibility issues with certain mods.

I would be happy if someone could help me with this

 

[Paul B]

The payment log also doesn't show any information about a payment.

If XF doesn't receive a callback then it can't process the upgrade.

You will need to check at the PP end and confirm that callbacks are actually being sent.

 

[Tempritscher]

If XF doesn't receive a callback then it can't process the upgrade.

You will need to check at the PP end and confirm that callbacks are actually being sent.

I don't understand the whole thing.
A few years ago, I just had to connect the PayPal IPN to the callback from the forum, and after that, everything worked.
Currently, I'm faced with a complete mystery. Everything should be set up correctly, and yet it still doesn't work.

Do I need to configure anything else besides the IPN?
The Xenforo2 PayPal (Legacy) function is used.