A question about wifi flash and webdav


I just bought the device

My needs are very specific, I want to use it with Raspberry device (wifi) as a mean to extract logged data

The Raspberry will identify the new wifi, will join, mount and then transfer the files

So currently I am playing, till it all works fine

  1. I am able to mount the device on my ubuntu machine and see the files. But when I add files to the mounted device it disappears (usually after few seconds or when trying to edit again). Is there a special mechanism I shoud use  for Webdav?

  2. Once I added files (not sure it is connected) I can no longer access the device with Sandisk Android utility, I can see it but not open it. I can access from Android using webdav file tool. FActory reset did not solve the problem 

Any clues?