Video Keeps buffering in Visual Comparison Page

[wpt_user]

Hi,
After running the test I try to watch the video of the run but the video keeps buffering and the server doesn't reply.

Config:
- Server: Default settings with only locations.ini modified
- Agent: New python agent with all the dependencies installed

Things I have tried:
- Re-installing ImageMagick, ffmpeg according to this thread: https://www.webpagetest.org/forums/showt...?tid=15185
- Changing Apache2 conf to allow mp4 files (didn;t work)
- Configure read/write permissions to allow user (www-data) to access the directory

The weird part is that I can access video.png/labels.txt files for a given test. The video is created and stored on the server as well but i cannot play it via the browser. However, I can copy the video via ssh (scp) to my computer and play it just fine.

Any help would be appreciated. Thanks