Help troubleshooting a home w/ walk-out basement!

I have a house I made based loosely on a childhood home that included a walk-out basement. Now for some reason that I cannot figure out, the front door, and the sliding door leading to the deck do not work as they should. I'm unsure why, as I built this house without any CC and also without cheats except MOO when placing some plants around.

Would anyone be willing to fuss with the build and see what exactly is broken, and why? And if there's a way to fix it at all?

I was really excited to have the ability to play with levels of houses like this, but I think my first try messed something up. :disappointed:

Luckily the sims can get in through the carport door near the kitchen, and can... unfortunately, go all the way downstairs and through the basement up to the deck lol. But that's not ideal and ruins the flow of the house.

https://athena.thesims.com/v1/images/1/0x00001f6e/4FCB0A71-07CA-11E9-8329-B573E4FD424D/00.jpg
https://athena.thesims.com/v1/images/1/0x00001f6e/4FCB0A71-07CA-11E9-8329-B573E4FD424D/03.jpg
https://athena.thesims.com/v1/images/1/0x00001f6e/4FCB0A71-07CA-11E9-8329-B573E4FD424D/02.jpg


https://www.ea.com/games/the-sims/the-sims-4/pc/gallery/4FCB0A7107CA11E98329B573E4FD424D?category=all&searchtype=ea_origin_id&sortby=downloads&time=all&searchquery=thecatsred13&max=50&maxis=false

Link to the gallery is here.