Wrong bones when importing non human rig from 3DS Max

Hi, I’m trying to import a simple turret into Unreal 5.1.0. It only has two bones (one for the body and one for the head/scope). I tried a lot of different options and things when exporting it but Unreal always take the “turret” (mesh) as if it was the only bone existing (in 3DS Max it’s not even a bone). If anyone wanna take a look, I uploaded the .max file. Thanks in advance.

turret.max (880 KB)