Android tablet file copy hangs directory opus after one file copy

Long story long.
When I attempt to copy move or delete multiple files from or to my galaxy note 10.1 (kitkat) to any other drive, DO will hang after copying (or deleting) only one file of the set.
If I disconnect the tablet, re connect, refresh DO I can copy, del or move another file but again, not multiple files.
Any ideas anyone???

The same file commands using windows explorer are fine. DO v 11.19

Appears to rectify the issue.
Thanks.