youtube-iframe-api closed captioning troubles - youtube-iframe-api

Question

Spent a better part of yesterday 6/12/2017 trying figure out why my captioning was not working when I was using the YouTube iframe embed code (generated from the Share > Embed button).
After much experimentation, I narrowed the problem down to what has already been identified. Closed captioning was not working as the captioning was automatically generated. Once I manually created the closed captioning, everything seemed to work fine. I didn't even have to use the cc_load_policy=1 parameter.
BUT... Today 6/13/2017, I happened to be working with the same video files and all of a sudden I got different behavior. When I play the video from a regular YouTube page, I see the captioning. When I play the video from the iframe embedded players I do not. Tried all sorts of goofy things to get things to work based on reading.
recreated the english closed caption (manually created a blurb at beginning).
set the cc_load_policy=1 parameter
set yt:cc=on as a tag
some other goofy things that are not worth mentioning.
CAPTIONING
note: In both cases the domain was: http://www.youtube.com I could only include 2 links in post.
/watch?v=EExO_6PVIXk
NO CAPTIONING:
/embed/EExO_6PVIXk
/embed/EExO_6PVIXk?cc_load_policy=1
I am at a loss. Any direction would be appreciated.
John

Answer 1

Heard through the grapevine that something changed with the YouTube iFrame API yesterday (6/14/17) where CC started to work.
With some testing, I got mixed results (but am working):
1) As of now (6/15/17), the embed video links now show the CC button and will show CC if you had previously enabled closed captioning (kept track in local storage under "yt-html5-player-modules::subtitlesModuleData::module-enabled".
2) If you provide documented the "cc_load_policy=1" parameter to the URL (of the iFrame embed) closed captioning will show regardless of the value in local storage.
3) What didn't work is me loading the iframe as follows:
<iframe
id="futusign_youtube"
style="visibility: hidden;"
frameborder="0"
src="https://www.youtube.com/embed/XIMLoLxmTDw?enablejsapi=1"
></iframe>
and then trying to set the CC policy in playerVars:
var player = new window.YT.Player('futusign_youtube', {
playerVars: {
'controls': 0,
'enablejsapi': 1,
'showinfo': 0,
'rel': 0,
'cc_load_policy': 1,
},
events: {
'onReady': onPlayerReady,
'onStateChange': onPlayerStateChange,
'onError': onPlayerError,
}
});
4) The work-around is to set the cc_load_policy=1 on the URL of the src to the iFrame.
<iframe
id="futusign_youtube"
style="visibility: hidden;"
frameborder="0"
src="https://www.youtube.com/embed/XIMLoLxmTDw?enablejsapi=1&cc_load_policy=1"
></iframe>

Answer 2

I think this might be a duplicate of this problem:
Embed Youtube with Captions on by default not working
...where adding the cc_lang_pref=en option (if you want English) solves the problem.