oh I see what the problem is. newsblur is trying to hit the web page instead of the feed url. so when I updated the feed to this url, it works
https://openrss.org/feed/programming.dev/c/linkedinlunatics@sh.itjust.works?dataType=Post&sort=Active
but that is a pain to have to go back and add /feed/ to every openrss url.
I can see on the web page version that it has auto discovery url pointing to the correct place. so looks like Newsblur isnt respecting the autodiscovery RSS link on the page.