It has to be likely that the clutch is still to blame, but these vans do have an issue with the clutch cable on some models.
How does the pedal feel? With a new clutch it should be very progressive, with little clearance at the top of the pedal stroke.
John
Sure, the gear selection is done courtesy of two cables - and they need to be adjusted perfectly to prevent gear selector wear in the gearbox itself.
However, I'm on about the clutch cable here.....if its inner cable is stiff or snatching (they did suffer from heat scorching at one time) then the clutch may not release properly.
As the gears appear to select correctly when the engine isn't running, it would appear to be a clutch issue - either cable or careless assembly when the new clutch was installed.
John
The cable will self adjust courtesy of a mechanism fixed to the clutch pedal, I guess......but I must confess I've never changed one.
Maybe a Renault forum could point you in the right direction?
John