BMW 320d 2005


I have a 2005 reg BMW 320d completed 133000 miles 6 speed manual gear box. I have already changed the clutch and the flywheel a year ago and still under warranty. I recently started having problem in putting the car to 1st gear in the morning and sometimes the 1st gear gets stiff and hard to come out as well. No issues with any other gears selecting. When the car is warm there are no issues in selecting the gears. And also I have tried when the engine is off and have no problem in selecting any gears.

Can you please advice what will be the problem as the dealer is saying its the gear box and i have spoken to one of the engineering company have deals with the reconditioning the gearboxes they said nothing wrong with the gear box its the clutch.