Hello there @flosee!
Yeah, this issue pops up from time to time in the community. Most of the times, what you are seeing is that the download is indeed complete, and the system is just unpacking and arranging the install, which depending on the setup, can take a surprising ammount of time.
My suggestion would be to leave it running for a bit. Yet, if more than an hour passes, and no changes appear, it would be worth checking if any of your security measures are blocking the process. You can also use the “pause” button in the install, and unpause it after a bit.
If the issue persists, I would restart the installer with admin rights, and temporary pause any active security until the process is completed (just remember to re-enable security afterwards).