Sims won’t go upstairs despite there being no obstacles

I have Sims 4 on PC with all the expansion packs, all the game packs, and a fair amount of stuff packs (I’m not sure if this is important or not hence why I’m saying it). My sims won’t go upstairs. There’s nothing blocking the staircase down or up. I’ve tried resetting sims and the stairs (selling them and then readding them). I’ve used this house before with the exact stairs and it was fine. I attached pictures as well (sorry theyre bad, I had to take them on my phone). I can’t figure out what else to do? TIA! 🙂