manual shfting with clutch Logitech G25 not working

Hi, have a little problem. I don’t need to press my clutch when I set the settings to"shifting with clutch". I just need to put the gear lever in to the any gear and that’s it. Any ideas?
And… the clutch works… when I’m pressing, the car won’t accelerate. I really don’t get why I do not have to press it when shifting.