FileDocuments and images are commited by the file manager widget. You need to add a cancel microflow that will delete the object (and with it the actual file from storage).
I have that issue every time I used images or files, I do not know why.
But if a user upload an image, and call a microflow after that upload (no matter which microflow), the object is being commited.
because of that I had to delete the images(or the files) if needed inside the next microflow clicked by the user.