I have similar problem. Currently i play get together. I create a new group to hang out at library. The club do list is - read，write， be friendly. The strange things happen is the sims just pickup a book for a second ， then put down on floor and pickup another one ， then put down again. Just one hour later， the library floor and table fill with books and actually they havent sit down enjoy books nor talk.
I have tried repair the game, put save folder etc to destop and reset games. Its happen continuously like this in group.
Edit remarks： i never use any mod
That's probably what you're referring to: http://answers.ea.com/t5/The-Sims-4-Bug-Reports/Sims-in-club-meeting-stop-reading-to-pick-up-new-books/td-p/5024139/jump-to/first-unread-message
This is supposed to be fixed in Patch 1.16.61
Taking feedback before marking it as solved and removing from the list
I am still having this issue with my sims and I have used the latest game update.
