Did you read my post? It literally states that the firmware you are running has the problem you are describing, and I listed it before you mentioned you were running it.
Probably need a firmware update, the firmware numbered 073.xxx.xxx.34540 for instance would do that with some NAS and many Server 2012 setups.
The firmware I linked specifically for your device not only fixes the issue, it is 9 levels newer.
If you ever want to know when a firmware was made, you can by the numbers themselves, but it is not higher = newer.
General release: 073.xxx.075.34540 - 5= 2015. 345=day 345 of the year. 40 is respin 4. = December 2015
New SPAR release: 073.xxx.177.14300 - 7=2017. 145=day 145 of the year. 00 is respin 0. = May 23 2017