No feed items collected

I made two categories with existing feeds (I checked if feed URL is correct and if they have content > yes), but not a single feed item was collected to the Curated RSS Aggregator plugin from these sources. I tried “Refresh all RSS links” – but nothing happened (I tried several times). This plugin sounded very promising (at least in the paid version) but if it is not able to collect any feeds it′s useless. What could I do to make it work?