I hear a pop/click everytime i start playback with (Renoise Redux) in FL STUDIO 10.
It does not matter from where i start in the song.
Have you loaded a sound/preset into Redux - which one?
And also, is the “sync” playback feature enabled? This will make the selected phrase (if any) play automatically, synchronized to the host.
So - in case you’re triggering some sample that happens to click, this would be why they are triggered in the first place.
And finally, perhaps there is some kind of “auto suspend” feature (think it’s called "smart disable in FL Studio) that could be interfering with the Redux output.