ipad pro will no longer recognize SD card

Until the last system update 13.4.1 my iPad Pro easily transferred photos from SD card using Apple lightning adapter. Now it does not even see that a device is connected. Other devices work in the lightning port on the iPad, and the SD cards are easily read in both my computers. I bought a new Apple lightning adapter thinking the adapter was the problem but it doesn’t work either. If it isn’t the cards, and isn’t the port and isn’t the card adapter, what is it? How can I download photos?