NPC will jump off stairs when hitting platforms.

[Eillis]

I have a house like this:
https://steamcommunity.com/sharedfiles/filedetails/?id=3164085029

NPCs will sometimes go out and navigate the stairs but I have a very hard time trying to make them navigate multiple floors.
I've searched all over. It seems that many players are having issues with NPCs to use stairs, but it seems there is no reliable solution for multi-floor houses (?).

I noticed that NPCs will walk up stairs no problem, as long as they don't hit their head on any obstacle. Unfortunately "obstacles" include platforms, which is just silly.

When you make the standard, intuitive stair design with a platform above (serving as floor for the upper level), NPCs will start going up but fail midway.
If there are no platforms above stairs, NPCs will go up fine.

Is this intended behavior? Is it some bug?
I started playing Terraria recently. Was this behavior any better in the past?
Are there any plans to change/fix this?
Are there any mods, which improve NPC AI to be smarter/more active?

[cheesenuggets]

its a problem everyone has, npcs never navigate multiple floors unless forced.

[Smetrix]

That’s just how NPC path finding works in this game, and that’s basically how it has always been.