Firstly, if your filters are working OK, then the items that are to be downloaded will be highlighted in green. That will at least sort out whether this bit is the problem.
Secondly, check your Log for error messages.
Thirdly, there is a long-standing problem with the tvnzb.com site - actually two problems, first with the sometimes failing database connections, second with the faulty implementation by the site of gzip compression, as reported in this thread among others:
https://www.altbinz.net/forum/index.php?topic=2538.0There's little that Alt.Binz can do about this (SABnzbd users report the same issue). Alternative: try nzbs dot org (register first and click on RSS link for instructions to use direct downloading from feed) or tvbinz dot net (no registration, click on Help link for feed info).