Found it. Your feed was fine and the YouTube fetcher was working. NewsBlur fetches YouTube through their official API, and that API has a daily quota that resets at midnight Pacific. Over the past week the number of YouTube feeds on NewsBlur jumped 13x, almost certainly people fleeing YouTube’s broken RSS feeds, and that blew through the quota partway into each day. Every YouTube feed would then stall until the reset, which is why your videos showed up 8 to 14 hours late and always overnight.
I deployed a fix that cuts the number of API calls per fetch by a third and makes quota failures visible so feeds back off instead of hammering a dead API. I’m also requesting a quota increase from Google. You should see videos show up starting tomorrow, as there will still be a stall late in the day until the bigger quota comes through.
To answer your question, the gdata URL you’re subscribed with is ancient but works fine. NewsBlur recognizes any YouTube URL and routes it through the API, so no need to resubscribe.