So I found what was the problem by enabling “Trace” logs. For those having the same issue as me :
It was coming from Prowlarr RSS, it does not used the “real RSS feed” of my torrent indexer (YGG), and in Prowlarr I had set up to sort by seeders, so when it would go check the RSS feed, it would search for the most recent results but sorted by seeders. To fix it I had to put in Prowlarr sort by published date, so I get all the recently aired episodes in the RSS feed.