Import new audio file version does not overwrite version in pool

Hold shift while dragging the file onto the event in Cubase.

Files are not handled the way you describe in Cubase – that’s to say, importing a file with a given name does not replace an existing file with the same name. Plus these observations should be made:

What files are listed in the pool after you do the second import?

What are your settings regarding the files being copied or not to the audio folder?