NewsBlur is unable to detect a feed on https://blog.dbrgn.ch/ but it seems to work importing the feed directly
<link href="https://blog.dbrgn.ch/feed.atom" type="application/atom+xml" rel="alternate" title="blog.dbrgn.ch Full Atom Feed" />So the site works fine (http://www.newsblur.com/site/3619165/blog.dbrgn.ch) but it looks like the feed finder is timing out. I just increased the timeout and it now works. Thanks for letting me know!