Yes. A course video reopens at the last position UNI recorded for you, and that position is saved periodically while you watch, not only once you finish the lesson.
The player saves your position as you go
While you watch, the player checks in with the server roughly every 15 seconds and stores wherever you are. Crossing 90% of the lesson's length still marks the lesson complete, and a position is saved at that point too, but you do not have to reach it for resume to work: stop at 40% and the lesson will reopen close to 40%, not at the beginning.
Resume needs an enrolment and a signed-in account
The position is stored against your enrolment, not against your browser. Watching signed out, or signed in without enrolling, stores nothing, so every video starts from the beginning however many times you open it. Enrolling versus watching covers what an enrolment turns on.
Because it hangs off the account rather than the device, the position travels. Stop on a laptop, open the same lesson on a phone, and you are at the same point.
Two cases where it starts from the beginning on purpose
- A stored position under 5 seconds is ignored. Seeking to it would be indistinguishable from starting fresh.
- A stored position within 10 seconds of the end is ignored. Reopening a lesson at its closing seconds is rarely what anyone wants, so it starts over.
What resuming looks like
The player seeks before you press play and shows "Resumed from 22:23" for four seconds. Nothing is locked. Drag the seek bar wherever you want; the stored position keeps updating as you watch.
To come back to an exact moment, leave yourself a note
If you want to return to a specific second rather than to wherever you stopped, add a timestamped note before you close the lesson. Its time chip seeks the player straight back there, and lesson notes stay private to you unless you decide otherwise.
If a video stops mid-session and will not start again, that is a different problem: see course video stops playing after a few hours.