Hi,
Could you please write the name of the archive file you have downloaded? If it's Door_in_my_old_home_pck.rar it shouldn't happen. Older rar file had this issue (due to some Godot saving trickery) but this one is fixed. I will be glad if you answer quickly so I can fix the issue.
If you still don't believe me check the code yourself, you can find project's repo page on the page