Aha another 2.4 owner with clutch issues the same as mine!!
Mine has been doing the same for nearly 6 months.
The pedal sticks down on gear changes.
Sometimes in the morning it goes flat to the floor and doesnt come up again.
I have got so used to it I hook the pedal back up with gear changes and tend not to notice it anymore
On mine they have replaced the clutch assembly, friction plate, master cylinder and slave cylinder over the course of 4 visits, and guess what the same problem still remains!
Im almost glad someone else is reporting the same problem as I am sure they think im making it up sometimes! Unfortunately for me there has been no resolution and the car will be returned to them next month with this outstanding.
The only thing they havent replaced which I think stands a chance of curing it is the pedal box.
Good luck with yours, and give the dealer hell - this should all be warranty FOC!