Feed won't update because of expired SSL cert, but Newsblur reports it as "OK (200)"

https://www.skorgu.net/hn.rss

The above feed had it’s Let’s Encrypt cert expire 2 days ago so newsblur hasn’t pulled in any updated stories since Sept 9th, however when inspecting Site Settings newsblur reports “2018-09-11 10:24:34
OK (200)”

Is it possible for Newsblur to log/report that error and display the “!” feed broken icon? Alternately, the actual RSS is updating fine on the server side, newsblur could just choose to continue importing stories even with an expired cert