Machine is during warming up state after copying every two sets for 20sec on following condition:
Note: Machine has not finisher.

İf you choose duplex and sort criss-cross, machine waits 20 seconds after every two sets copy (A4+A4R).
İf you try to copy with duplex and only sort, no problem.
If you try one side copy waits after every 4 sets for 20 sec. and going on. it displays ''warming-up'' when waiting.

do you have any experience about it.