I started a new game after the update and my sims were walking around the house to go up the back stairs and then teleporting to the front stairs to go inside. Then I tried to delete the front stairs and they didn’t just highlighted. Then went into live mode and the back stairs were gone and they were trapped on the foundation because the front steps wouldn’t work.
Yeah the stairs in my game are bugged too. It's the exact same as what is happening to you. I hope there is a fix soon.
You can download the Stuck Object Remover mod and remove it that way. It works, but leaves some parts of it - that can be also removed with the use of FORCE ERROR after turning on the boolProp testingcheatsenabled true mod. Then you’ll be able to put new stairs, everything works if it’s a residential lot. I recommend using various types of stairs so that it doesn’t turn into a teleport portal. I have the same problem and it works but can’t figure out how to do it on the community lot / apartment one since I can’t play in live mode there 🥲
