I have this problem too, but not just with plan lecture. With every stay at home task. I believe the problem started after my sim got to level 6 of her career (administrator) or perhaps it was at level 5. The earlier levels were fine.
No matter if it is plan lecture, faculty meeting, tutoring a student, write grants... She will suddenly up and leave the task to read a book, or put a book back on the shelf. Once she leaves the task all progress is lost, she starts it again from scratch. The only way to make her complete anything is to watch her VERY closely and x out any attempt at another interaction. Or turn off free will. Which I find extremely boring, and should be unecessary. The lack of progress is also an issue with free will - if the computer breaks you're still at scratch when starting the task again...
I notice this thread is a few weeks old but gonna say I'm having the same issue with the Education Career. I was able to do work from home tasks at first -- and then suddenly every time I start a task on the computer, after a few minutes they randomly get up to read a book. And when I cancel it and go back to the computer, the entire task has reset again.
No mods or anything like that. PC.
