Am able to get USB drive seen in beta 1, didn't try it in beta 2, but definitely not being seen by Files in beta 3 for iPadOS. No problem with drive being seen in iOS13.
Saw note about needing to format an HDD to APFS to be seen, but obviously you shouldn't need to do that for a thumbdrive.
Same problem in iPadOS 13 public beta 2. USB flash drive not recognized at all in files app. Also wired mouse not working nor is wireless mouse with its own USB dongle. It seems that the USB camera adaptor isn't working for any device I have tried plugging in.
funny thing is, I plugged the dongle into my iPhone XS Max running iOS 13 Beta 3 and it recognised the usb drive.
Go figure....
Excatly the same observation for me ... it works on iOS and not on iPadOS.
Same here, all devices connected to the lightning port remain unseen on my 10.5 iPad pro with iPadOS beta 3
