Hi,
well for me (at least when I did download your file) there are two objects in the file.
One object is the black square (which you call background I guess) and another object is the text.
Both objects are not grouped and single, independent objects.
As mentioned above, for this it sounds logic for me, that whatever I do with one of these objects, has no impact on the other object.
And this is the behaviour I experience, using your file.
You can move the text away from the square (background) somewhere else. Now change the text.
The square should not be touched in any case. Same, like when you place them on top of the other.
Again, this is what I experience, dealing with your file.
regards