@TeamYouTube, I resolved my issue on my own. Further digging gave me the idea of disabling the ad-block extension that I've had on chrome for a decade. Was this an intentional 'update'? I'm premium, so it doesn't bother me; but be prepared for the angry masses when they wake up.
@TeamYouTube Premium does not seem to be the issue as Premium works while incognito. https://t.co/MXPelS16Ob does confirm this is not a local device issue; or if it is, it was pushed from the site itself.
@TeamYouTube@ohmeqa Just jumping on this one instead of making my own. I'm having similar issues. Chrome is my default browser. Video playback stopped functioning at 2:20 PST. Going incognito returns functionality only while in incognito. Cleared cache, history, and cookies.