Strange behaviour related to Fire Base Project Bucket not empty

I just discovered a strange behaviour of the Fire Base component, due to the Project Bucket set at design.

My app was malfunctioning when it requested reading tags from a Fire Base Data Base:
When I requested a tag contaning a value, the reading was 0, despite I could see in Fire Base console that the real value was 14.
When I requested a tag containing a list of lists, the reading was [,,] (all lists where empty, despite I saw at the console that they all have some content).

Then I remembered this other topic: "Empty Fire Base Project Bucket gets filled with anothers project name", and thought there could be some relation (may be I pasted or played with the database name lately).
I discovered that the project bucket (which should be empty for my app to work properly) contained the name of the project.
I erased it, and now verything works fine again.

What intrigues me the most is:
If the project bucket was wrong, the logical thing is that it would read nothing, or give me an error.
But, if it wasn't reading anything, how could it know where there was a value in the content of the tag (to put a 0), and where there was a list of three lists (to put them empty [,,])?
Is it magic?

Sorry for the question.
I just discovered myself:
When closing, the app saves a copy of the list in the database (at the wrong project bucket). And at restart, reads it again.
That's the explanation. No magic.

There is a peculiarity in App Inventor to remember:
Imagine that you want to make a new version of your project, and you set the project bucket of a Firebase component empty by design.
Be aware that, when you make a copy of the project with "save as", App Inventor will set the project bucket to the name of the old project.
If you do need the bucket to be empty, then you have to remember to erase the old project name in the design of the component, each time you make a new version of your project.
Or may be you prefer to force it to empty programatically at app start, using the set Firebase . ProjectBucket block, to set it to empty text.