Dell EMC Unity XT 380 Unable to delete a storage pool

Greetings,

We purchased a new Dell EMC Unity XT 380 for our company. While setting up the storage system, I made a test storage pool. After testing the system, I attempted to delete the test pool, but I was unable to do so. I checked to see if there was any host access to the pool, but there wasn't. Despite this, I am still unable to delete the pool. 

Could it be that the storage pool contained the first four system drives? What could be the reason for this issue? I am hoping to find a solution to this problem as soon as possible.

Thanks in Advance