With the new 3.17.4 version, RSSyl seems to have stopped working correctly with Youtube. Even if all RSS items have been marked as 'read', it still reloads the entire Youtube feed. Feed sources other than Youtube still seem to be working fine.
This has been fixed shortly after the 3.17.4 release. Sorry about that.
Excuse me, but in which version was it fixed? I have just updated to 3.17.4-1.1 (at least this is how its version is displayed in pacman) and the issue is there.
*** Bug 4295 has been marked as a duplicate of this bug. ***