If a dupe has started a lengthy task they will work all the way through break time.
Steps to Reproduce
Print a new dupe, preferably with zero build skill. Near the end of the cycle have them start building a granite painting. Watch them build that painting through the entire break time. I saw this once before on the hamster wheel but only once on that so far which is odd as my battery is rarely full so not sure if that's doing the same thing or not. Also possible this isn't a bug and the dupe skipped break time because it was their first cycle and they had no needs yet?
This issue has not been confirmed by a developer yet.