i get that too when i'm queing up actions (which you can q up 8 in a row ) some will just cancel out i hit the p which will pause the game i q up again then hit p to unpause usually that works most of the time lol if you have 3 or plates lying around click each one clean up to make sure a sim won't oversleep even if the rest bar is paritally green click the bed sleep option (otherwise sims will not go to bed and will keep going untill they pass out yep it happens they'll have a few zzzz on the floor once they pass out you have to wait for them to get up then tell them bed ) so if want your sim to wake up at a certain time you click on the bed option sleep once the sim is asleep then hover over the icon in the corner have sleep until fully rested 9am depending on what time you send them to bed at
also in the buy mode items are in order by price lowest to highest that goes for anything in buy mode so beds for one the cheaperst beds will give your sims the bad nights sleep moodlet the better the bed the better the sleep
p.s.
in everyone of my games i have sim that has the neat trait that sim keeps everthing neat and tidy and will just do their own thing while you concentrate on your main sim just don't forget to send your sims off to the park or tour movie tour science centre otherwise they will get a stir crazy moodlet if they have been inside too long then sending them off somewhere will help unless a sim has the hates the outdoors moodlet then they love to stay inside