Only the first four controller devices are available to be selected

In order to use my x55 HOTAS I must disconnect other devices first, VERY frustrating. This is much the same as the original Automobilista for example, which has a USB device limit of 6, it wouldn't see past the first 6.

Weird with all my devices it gives me two flight sticks, of which I can choose out of three of my devices. If I disconnect most of my devices, suddenlt it gives me four flight sticks of which IO can choose four of my devices, very odd behaviour!