iPhone 13 mini usb connection

I am a user of drones and am having a problem with an iPhone 13 mini.

I believe the device connects via lightning cable to usb-c to the remote and connects to the remote as a usb drive would - the problem is that the remote is not connecting.

The iPhone charges fine but have also noticed that when I connect an sd card reader to the iPhone 13 mini - the card is not recognised in Files although it has in the past.

Have tried with an iPhone 11 Pro in both the drone remote and sd card are both are read correctly.

is anyone else having similar issues or knows of a fix?