If you are using original Lightening Adapter then I do not see why they are not reading the SD Card.
You can import photos and videos from an SD card, digital camera, or other supported accessory to your iOS device using one of these:
- Lightning to SD Card Camera Reader
- Lightning to USB 3 Camera Adapter
- Lightning to USB Camera Adapter
- iPad Camera Connection Kit, which contains both iPad Camera connector and iPad SD card reader
If you're using a Lightning to USB 3 Camera Adapter, these iPad models transfer data at USB 3 speeds:
- iPad Pro 12.9-inch (2nd generation)
- iPad Pro 10.5-inch
- iPad Pro 12.9-inch
All other adapters and iOS devices use USB 2 speeds.
Supported SD cards and image-transfer protocols
- SDSC
- SDHC
- miniSD
- microSD
- MMC
- SDXC