If the machine has several turrets, they are incorrectly selected when installing the pylon.
On the video. The helicopter has two turrets. If you select Gunner, it will change to Gunner 1 when you click ok. And vice versa.
[[ https://www.youtube.com/watch?v=-eKHGqRSh7E&feature=youtu.be | https://www.youtube.com/watch?v=-eKHGqRSh7E&feature=youtu.be]]