Sims can't go up/down stairs after Snowy Escape update

Product: The Sims 4
Platform:Mac
Which language are you playing the game in? English
How often does the bug occur? Every time (100%)
What is your current game version number? 1.68.156.1220
What expansions, game packs, and stuff packs do you have installed? Every EP except Snowy Escape, Eco Living, Get Famous and Get to Work. All GP's except Strangerville, Vampires, Jungle Adventure and Journey to Batuu. Patio Stuff, Tiny Living, Laundry Day, Toddler Stuff, Moschino and Movie Stuff.
Steps: How can we find the bug ourselves? Go into a pre-made home/lot made before the update and try to make a sim go upstairs.
What happens when the bug occurs? Sims wave their arms as if something is blocking their path.
What do you expect to see? Sims walking upstairs
Have you installed any customization with the game, e.g. Custom Content or Mods? Not now. I've removed them.
Did this issue appear after a specific patch or change you made to your system? Yes
Please describe the patch or change you made. Update 11/10/2020 (Mac: 1.68.154.1220)

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Sims can't go upstairs or downstairs in any of the homes I've built pre-Snowy Escape. Before I thought the issue was only on configurable stairs, but when I switched households, I also noticed it in the pre-made lot in Windenburg, Factory One. My sim's pet however, went up and down the stairs just fine. So far the only workaround I found is deleting the existing fence/guard railing and placing a new one in the same exact place on regular stairs. For configurable stairs, place the fence around the outline of the stairs. The fence/room trick to delete those extra tiles surrounding stairs seems to be the issue for the configurable stairs. I'm not sure what's causing the problem on regular stairs. Everything worked fine before the update. 

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