Yes, the Mature Warning does appear.
Yes, the channel i am attempting to view with the embed is a channel with their Mature Content flag set to True.
However, there are 2 different embeds. An “interactive” one that accepts mouse and keyboard input, and a “Non-Interactive” one that has all user interaction disabled, INCLUDING pressing “start video” button on the Mature Content Warning Overlay. Using the “Non-Interactive” embed, NO amount of mouse clicks on the “Start Video” button remove the warning overlay.
The “Interactive” embed works perfectly fine on Mature channels. I can get past the warning overlay and use the playback controls. The “Non-Interactive” one, basically, is completely useless for any channel that is set up to be a Mature channel. ALL you can see is the Warning Overlay, no stream video or audio what so ever, since that warning cannot be bypassed due to no valid forms of interaction.
That is why I am wondering if it was intended functionality for the “Non-Interactive” embed to not work with Mature channels at all, since it requires user interactive to agree to the Mature Warning.