Cancel iTunes backup and restart?

I started a backup earlier and unfortunately could not finish it, but I also could not cancel it correctly and removed the iPhone from the plug. Now I wanted to start the backup again, but it seems as if the other one is still in the process of loading, it is already completely finished, but does not move anymore. I can't cancel it, start another one. Restarting the iPhone and laptop does not help either. Anyone have any idea how I can cancel the backup (which is not yet saved on the laptop and therefore can't be deleted) and start again?

It is also unwise to unplug your iPhone in the middle of iTunes backup. You can delete the old one from iTunes backups and create a new one. As an alternative, I would make a backup in the iCloud (that's how I do it) because it syncs whenever I'm in the WLAN and I don't have to do anything.

Open iTunes, delete the current backup there and then create a new one.