I don't know if this is a common observation but ...
I've found I can only FTP into the Aura using a wired connection. For some reason trying over WiFi fails for me. Also, the FTP server often seems to crash. Turning the FTP off, allowing anonymous, not allowing anonymous and turning FTP on sometimes resets it. Other times I have to reset the IP address etc. Rebooting is another option.
A third party file management app with FTP server might allow WiFi access, but the location of the recordings is a bit obscure.