Newsboat / Newsbeuter is not loading old feeds

I use Newsboat for quite some time now and I really leared to like it's plain neatness. However, whenever I add a new feed Newsboat it loads only 10, sometimes 20 (?!) articles that are older then now.

I'm really quite some long time on this, but I can't find the settings (if there exist) how to force to load all (or let's say <1000) articles back in time from the moment of subscription.

Please note:

max-items 3000

is already set (see documentation). I want to force newsboat to download more old articles not to keep them longer.