USB Host Mode - device access permission granted but not remembered

Question

I have a USB Host Mode application that works perfectly. I plug in the device, Android pops up the Allow the app APPNAME to access the USB device? permission r

Answer 1

I answered this here, although I gather that duplicates across other SE sites are permitted.

In answer to why, it is as you surmised in said thread; because with your hardware you get different identifiers each time you connect, e.g. /dev/bus/usb/001/, /dev/bus/usb/002/ and so on.