I am sorry you are having problems with your device but let me help you.
Please be aware that we provide a list of tested peripherals for NUCs. You can check this information here:
It is important to mention that if the device you have is not there it could be that it has not been tested or is not compatible. From our side we have not received reports about a compatibility issues with our NUCs. However, if you are testing other drives and are working fine could be related to compatibility problems.
I recommend you updating the BIOS to the latest driver we have for your system. You can get it here:
Besides updating the BIOS in your system, you can check for firmware updates from the ssd manufacture.
There are reports of other OCZ devices also not working in some NUC models - see the list at the bottom of this page: http://www.intel.com/support/motherboards/desktop/sb/CS-034601.htm
It sounds like a similar problem with the Agility model.