I bought a usb-c to usb-3 cable to connect my Nikon D800 to my iPad Pro and import the photos. Lightroom only sees the sd card, and not the primary cf card. The native Photos app sees both. Lightroom sees the cf card when plugged into a card reader, but not when plugged directly into the camera. Is this a bug/limitation, or am I doing something wrong?
which iPad Pro are you using? 1:st, 2:nd or 3:rd gen?
What adapter do you have connected to the iPad Pro?
I'm using an iPad Pro 11", the current model. Running iPadOS 13.3.1.
Is this about the CF card only or about both cards in the camera at the same time?
E.g. if you remove the SD card, and only leave the CF card, is it then read?
after reproducing the issue I can confirm that there seems to be an limitation with dual slot reading on iOS 13.3.1 (but not in iOS 13.3) for that camera and maybe even other Nikon dual slots cameras.
I would just use one slot until this has been fixed.
Lightroom Mobile 5.2.2 was released last week -- please try this update