After the sim in my active household went to work, I switched households to play another Sim for a little while. When I switched back, she was back at home even though she was supposed to be at work during that time, and there was no way to send her back to work.
I did note that when my Sim went to a different lot and then returned, I would get a message like "While you were gone, a Gardener visited your house and it cost you $90", even if the Gardener had been there at 9 am and my Sim got back home at 11 am. So my stab in the dark is that the Gardener mod mucks up whatever keeps track of or handles Sims being at work.
Thanks
