nginx – NS_ERROR_NET_PARTIAL_TRANSFER error when streaming video in Firefox

My site has video hosted on it playing using the HTML5 video element, but when streaming these videos in Firefox, after about 2 minutes the playback stops with an NS_ERROR_NET_PARTIAL_TRANSFER error and it won’t play past what it has already buffered to. This only occurs in Firefox, in other browsers the video continues buffering and plays successfully to the end. I’ve checked my nginx config and it has all the elements suggested in other answers to this question

    ...
    client_body_buffer_size 32k;
    client_max_body_size 32m;

    location / {
        ...
        proxy_buffering off;
        proxy_request_buffering off;
        proxy_connect_timeout 1200s;
        proxy_read_timeout 1200s;
        proxy_send_timeout 1200s;
        ...
    }
    ...

Also, the nginx logs for the mp4 files are showing a 200 status code with the correct number of bytes for each video. Is there something I can do or is this just an issue with Firefox?