Looking into it now!

Edit: No, the HN API is working:

https://hacker-news.firebaseio.com/v0/item/33790811.json?pri...

https://hacker-news.firebaseio.com/v0/item/33786127.json?pri...

The problem is likely at Algolia's end. They also have a nice HN Search API and most likely hnrss.org is using that one. I've contacted them and they're currently looking into it.

Edit: they've found the problem and are currently backfilling the missing data. If anyone still experiences trouble with HN Search after (say) 24 hours from now, please let us know at hn@ycombinator.com.