Okay, I was manually going through my subscriptions channel by channel, and decided to check the Subscriptions list. I think it's fixed now. The list is long as forget now for the same span of time, I'm seeing videos I wasn't seeing before, and the biggest tell is I can keep doing Load more (Highlights mode only lets you Load more 1-2 times).
So... Well they fixed it, so I can't go "forget you for taking so long" because, even though they wouldn't do anything, at least they did something about it...