@burnout426 I can say it's getting worst. At first it was maybe 2-3 videos a day that had this problem but now most of the videos I saw on twitter has this.
If you wanna compare two here is a link.

Length : 56 seconds,audio is gone after 9 seconds
https://twitter.com/erdalbiroll/status/1116473516684132352

Length : 44 seconds, audio is perfectly fine
https://twitter.com/Red_ZaZa_/status/1116575919215276033

Edit: Also the fullscreen solution works.When the video is fullscreen, audio spikes up at 9 second so it is either a problem about how opera handles .ts file extension or how Twitter streams these.If you go fullscreen before 9 seconds you can turn it back to normal and it works fine.

@burnout426 I can say it's getting worst. At first it was maybe 2-3 videos a day that had this problem but now most of the videos I saw on twitter has this.
If you wanna compare two here is a link.

Length : 56 seconds,audio is gone after 9 seconds
https://twitter.com/erdalbiroll/status/1116473516684132352

Length : 44 seconds, audio is perfectly fine
https://twitter.com/Red_ZaZa_/status/1116575919215276033

Edit: Also the fullscreen solution works.When the video is fullscreen, audio spikes up at 9 second so it is either a problem about how opera handles .ts file extension or how Twitter streams these.If you go fullscreen before 9 seconds you can turn it back to normal and it works fine.

Contacted devs about this months ago.They wanted bunch of information and than said they couldn't reproduce the issue and stopped responding.I still have this problem and as they can see a lot of people also suffers from the same thing.