Can't place stairs next to interior walls

I'd normally agree accept I've been able to place next to interior walls just like this all the time, and also it's telling me there's obstructions where there are none.  I've kept up testing and yeah still having odd problems with stairs.  Like it will go next to a wall in a blank room with plenty of room above and below for the stairs and then you try to extend it just one with a wall that also is the exact same it will stop saying there's obstructions, where there isn't.  I have other houses where I have placed stairs next to walls the same way.  I literally can not attach any stair to any wall that is not fully an interior one, and even then it's causing problems.