Unable to delete custom name through data command

I was unable to delete a custom name for an armor stand in order to create my data pack.

1. I placed an armor stand.
2. Named "test" it with a name tag.
3. I exected the following command:
   /data get entity [the UUID of the armor stand] CustomName
4. The following log is returned:
   test has the following entity data: '"test"'
   I could expect until this step.
   And now I want to delete this custom name.
5. I executed each of the following commands and verified with the command used in the 3rd step:
   /data modify entity [UUID] CustomName set value '' and
   /data merge entity [UUID] {CustomName:''} and
   /data remove entity [UUID] CustomName
6. The custom name was not deleted in every case.

If you know of a way to delete a custom name using a command, please let me know.