I have a plane trip coming up so I wanted to download some videos to watch offline. I selected a video on my Dropbox account to be available Offline, and after it finished downloading I tested it by putting my phone into airplane mode and the video does not play offline. It says "No internet connection." It is in my list of Offline files, and it shows a little purple icon next to it showing that it was downloaded, so why can I not play it offline?
It's an .mkv video and plays fine when connected to wifi.