dotcomUNDERGROUND I tried 'popup_video' => false,. That shows the context menu at the bottom in the white bar.
But still I can not go to next photo/video with left/right swapping like photos.
You can definitely not SWIPE if you are loading videos into the MODAL window instead of the POPUP, because the modal window does not support navigation. In next release, you can navigate from the modal with arrow-buttons, but you still won't be able to swipe.
I'm not sure why swipe does not work for you in the POPUP, but it could be your browser does not allow swipe over videos, because the interaction is used for something else. Try another browser?