We have correctly embedded YT Player using IFrame but on some devices the CC button is not visible when the video is running in portrait mode. However, it appears when we switch to Landscape mode.
Important to note that we are still able to turn off/on captions by going into the settings that appears at the right bottom near YouTube branding.
It appears that YT IFrame Player is designed that way to fit as per the available width but there is no official documentation stating that hence we are asking here.
We have used official YT IFrame player to show YT videos but the CC options doesn't appear when the device is running in Portrait mode while it appears when we switch the device to Landscape mode.
Setting the manual height and width work for few devices but that generates another problem of misplacing the origin of the player and certainly not the solution one can implement.