CMI5 Statements aren't sent until exit course button is clicked

I've been integrating rise courses into our LMS using CMI5 and I've noticed a strange behavior that the course doesn't send statements until the course terminates. (The user uses the button to leave the course). More troublesome is that if the user closes the tab they're in instead of clicking exit course those statements are never sent to the LRS. 

When looking at the network tab it appears that the course frequently updates the bookmark and that seems to work well but it doesn't send statements until right as its about to close. Is this behavior expected? Are there any workarounds to this? In our use case we expect many of our users will launch the course complete part of it and very likely not "exit course" but probably close the tab and launch again from the LMS next time they work on it.