Hi Abates,
This is something the team are aware of and is not occuring because of the update to 2078. Placing some items inside buildings has always been difficult and I have been passing feedback to the team from players regarding the ability to place items inside. If you have been able to place these items inside beforehand, please let me know as this would have been unusual for players to be able to do this. Workarounds for placing items inside can be found here: [Known Issue] Difficulty placing crafting stations inside buildings
With regards to your other issues, would it be possible to get images on what you can no longer do (if you have an older file you can reference) or what you wish to be able to do with the stairs? The more info and references I have, I have the better I can pass your feedback onto the team.