Sims cancel tasks on their own, won't use stairs etc.

[Caspin]

Hi, I really don't know what to suggest other than to move to another house. It sounds as though the stairs are bugged or something invisible is blocking the routing. You could delete those stairs and replace them in case the stairs are glitched. If they are cancelling actions in the queue even on the same level it sounds more like routing - is this a very small house? - or some other bug. You could also remodel the house, at least temporarily, to check the routing - for example put in a staircase elsewhere in the house (knock in a few walls if you need to) and see if sims can successfully use that to get upstairs and stay there. Remove some furniture so you can be totally sure that sims are not being blocked from moving.