Hi Brontemon, I'm seeing this too when using my browser. I'm not sure if this is a problem on our end or with the player we use (JW Player). I did find a temporary fix you can do. If you try to use the scrubber bar with the player window "not maximized" the scrubber bar and chapters don't work. However, if you then maximize the player to full screen the scrubber bar will work fine. And if you then go back to the smaller view the scrubber bar will now also work. However, if you then log off you will have to repeat the steps the next time you use your player as the scrubber bar stops working after you log off.
We're looking into this issue to see what is causing it. If it's on our end our developers should be able to fix it, but if the problem is with JW Player we will have to reach out to them.