Non-Euclidean level design - stairs

I am trying to implement some non-euclidean level design to my level and one specific effect i want to achieve is that when you go down a staircase poiting downwards you should end up walking upwards one floor instead of down one floor.
Here’s a concept on the effect.

And here are screenshots from Unreal illustrating how it looks when walking down the stairs and the up.
Walk Down
walk Up

I have some ideas i’ve tried out thus far.
First one i tried to make a portal (as the ones in the game portal) where you render the other staircase and teleports as you venture through, as i am a beginner in blueprints i really cant achieve this effect well.
I tried to fake it using a portal and lights which makes it complete darkness just before you teleport and then you see your walking upwards, but the illusion disappears alot here as you cant see the whole staircase throughout the process disturbing the illusion.

Another idea is to actually rotate the other side 90 degrees as the player walks down the end the floor is rotated 90 degrees so the player is looking down but actually its the other room. The problem here is that everything needs now to be fixed to work at 90 degrees rotation (gravity).

And if i use only teleporters in middle of the staircase the problem as a player walks through it is that the player still got the same view position so instead looking up through the portal it teleports into looking down into the stair steps.

Anyone got any good ideas or help to achieve this effect?

The staircase is planned to be pretty long and dark and tight.