I don’t know how you’ve done this, but apparently the studio testing is the appropriate result.
In the properties it says the current Y value that is different to the other parts which would normally result in that kind of behavior within that part.
In any case, this may be also the cause of the 0.001 digit, I never tried going that far down.
Regardless, I’d like to suggest to using something in studio called Archimedes, it’s a plugin that allows you to place objects that are connected.