Can't export logs

[brightpinefield]

I've been trying the export logs feature in my Bitscout instance but I'm not having any success exporting to a USB.

From the below images, I've inserted a USB drive "sdd" and try to mount "sdd2"

It looks to have mounted:

Select the Export logs:

Then try to unmount the drive to have a look at the contents but get this error:

Try to confirm the files on the drive but see nothing:

Am I doing something wrong?