Having the same issue since so long but now I've had it.. the audio stops after 8-9 seconds in most videos on twitter & returns at the end of video.. It's really irritating. Also making the video fullscreen solves the audio issue but freezes the video itself. What is going on!
Tried everything, only solution is to copy tweet link & watch video on other browser.
Using version 58.0.3135.127
Win 7 64bit