Emby version: 3.0.72 beta
Galaxy S9, Android version: 9, Kernel version: 4.9.112-15611914
Download to internal and external SD card working fine for me now, even completed ok when in background.
(1.2GB TV episode original quality.)
NOT able to download to USB flash drive in OTG adapter, which is not recognized by Emby, so not even selectable.
Also tested using an SD card in a USB 3.0 adapter fitted with with OTG adapter. Same result.
(I found using a flash drive in the S9 OTG copied incredibly slowly for some reason, but using an SD card with adapters worked at full speed.)
USB storage IS mounted successfully by Android and visible and accessible for reading and writing in other apps.
ES Explorer reports it's Readable, Writable, and not Hidden.
Edited by Wotu, 22 August 2019 - 01:17 PM.