I'm having weird issues with my internal SSD (named FusionDrive but it's no Fusion Drive). 

**Symptoms**:

 1. it gave itself a new cryptical name, and I can't change it back
 2. in most cases I cannot install new software anymore (e.g. I cannot update flash)
 3. It is sometimes shutting down immediately
 4. the Mac Harddrive Assistant says does not let me activate it, and even says "no errors found"


**See below for some screenshots:**

*Referring to Point 4 and 1* (says: Volume seems to be ok, see the weird name...)

[![enter image description here][1]][1]


*Referring to Point 2* (says: Installation failed)

[![enter image description here][2]][2]

**my counteractions so far**

1. ran the Apple Hardware Test. Result: nothing found.
2. ran the Hard Drive Test (see screenshot). Result: nothing found.

Any help is much appreciated! Wanna get rid of this :(

  [1]: https://i.sstatic.net/FVzse.png
  [2]: https://i.sstatic.net/PnQj1.png