Private Time Machine Backup Missing

Two months ago, I purchased a ReadyNAS 204 (firmware 6.3.5) with 2 x 3TB HDDs. The X-Raid was autoconfigured to use RAID 1. After moving about 500GB (+/-) of data to my NAS, I created a 1536GB (1.5TB) Private Time Machine backup for my Mid 2010 MacBook Pro running OS X 10.10.4 (only have about 284 GB of data on it in total) . Everything worked great. As of last week, I purchased 2 more 3TB HDDs and installed them in my NAS. After 2 days of installing the new drives, the X-RAID rebuilt all of the data using RAID 5 on all 4 disks. However, now I have two big problem.

1) According to the RAID 5 mathmatics, with 4 x 3TB I should have about 9 TB accessible to me. According to my "Volumes" page I am currently using 596.46GB of 7.59TB. What happened to the other 847.38 GB???

2) Furthermore, my Private Time Machine is no longer displayed under the backup page of my NAS. The weird part is my MacBook Pro is still backing up to my Time Machine on the NAS that I can no longer find or is no longer listed on the NAS itself. The Time Machine Perferences show the Time Machine as available, accessible and that it is still working perfectly fine and that I currently have 1.33 TB out of 1.54 TB available.

*Update: Right before I submitted this post, I restarted my NAS just to make sure it was a running bug. Now that I have restarted my NAS, the Time Machine on my MacBook Pro can no longer find the backup disk on my NAS. :'-(

Has anyone seen this issue, or know of how to go about fixing the problem? Thank you very much in advance.