M3U8 plays with sound on one app but without sound on another

Question

I have a user with an m3u8 file that the content of the file looks like this:

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=701214,CODECS="avc1.66.30, mp4a.40.34",RESOLUTION=640x360
chunklist.m3u8?wowzasessionid=1635263674

He claims this other app (not mine) is able to play that file with sound on the Chromecast whereas mine plays it without sound. I have not been able to reproduce his claims but since he insists this is true I figured I would check.

I'm using the reference player code pretty much unmodified except for this code which I got on this other post:

host.processManifest = function(manifest) {
    if (manifest) {
        return manifest.replace(/CODECS=\"avc1.66.([0-9]*)/g, 'CODECS=\"avc1.66.30');
    }else{
        return manifest;
    }
};