I’m on commit v18.12 (b6a0214, and running php 7.0 with nginx 1.10.3 and postgres 9.5 on Ubuntu. Chrome 71, Windows 10. I just checked, same problem in Firefox 63.
I use J/K to move articles and sometimes I’m getting articles with no content in them, even from this forum. So I’m not sure if that’s the issue, because that seems odd.
But either way, when I have a no content article and I hit J it skips over the article with no content and even marks it read. I’m seeing this on other feeds too, but don’t have an idea which ones off hand.
Hitting K does take me back to selected on that no-content article as well just fine.
e: I should’ve check before, and I could definitely be mistaken, but it does appear that the empty article is in the RSS feed. So that probably isn’t the issue.