Jo-Ann,
Your tips fixed it. I had to delete the lower two sets of stairs, replace them and uncheck the "allow wrap" on both and it worked.
The walls were not marked as "no room definition."
Thanks for the replies.
I am having trouble stopping a pair of stairs leading to the same landing (merged stairs 1.jpeg) from automatically merging (merged stairs 2.jpeg). If I make the more narrow set of stairs in the first picture wide enough they automatically merge to create the stairs in the second picture. Seems like there should be a checkbox to check or uncheck somewhere to prevent this from happening.
My internet search and looking through the software preferences and specifications has been fruitless so far.
Thanks,
Tim
Home Designer Pro 2017
Mac 10.12