Autotiling is buggy with this tileset. Check out this pic.
Hi there!
That's not a bug, it's the autotile logic of RPG Maker which is a bit complicated to explain. You used A3 tiles for creating the roof, but A3 tiles can only create rectangular forms in RPG Maker by default (I wonder why, never understood it either, to be honest). A3 doesn't have roof corners. You can alternatively try to use the A4 autotile which also has got roof corner tiles. Some of the options on A3 and A4 in the Futuristic Cities tilesets are the same.
For the door you may want to use a method called shift mapping, so that the autotile doesn't create edges that you don't want to appear at all. Here's more information on shift mapping: https://forums.rpgmakerweb.com/index.php?threads/shift-click-mapping.14387/
In RPG Maker MZ, you don't necessarily need shift mapping. MZ offers layers for mapping, so you could place the door on a higher level than the autotile and things will work just fine.