Our anti-cheat system did not detect the method used by this person.
The method he used: Ai. change the file. We knew that he normally used it for damage boost and similar works, but this person was dropping items to himself and this item was only in his hand. He can do anything he wants.
Has anyone experienced this before and know the solution?
There are a lot of attack vectors exposed to cheaters if you’re not careful. You’d have to give a little bit more context such as; what scripts you’re using, what the cheater accomplished, what you managed to detect and what you didn’t.
As said above, securing your events is a smart solution. However learning your codebase and looking for different exploits in it yourself is a lot smarter than simply relying on an anticheat.
If you believe that the cheater is abusing some sort of AI file within their game files, you can enable the pure mode server option, which prevents them from doing so.