Hi @bilalashraf -
It is possible this is due to popup blockers or network filtering, though an update was recently released that should have resloved this. If you have any popup/ad blockers running on your browser or network, please disable and try again.
DM me if you are still experiencing issues.
I also noticed video and audio out of sync, audio sometimes repeating itself, so I had to stop watching the video and read the material instead. I believe the course was DO180.
I have no popup blockers or network restrictions.
@ericbos Our Video Classroom player also includes the ability to change the bitrate. Perhaps try changing it to a lower kbps to achieve better playback. If you come across the exact video(s) that are giving you issues you can also post them here for us to investigate.