The aircraft has a problem !
Clearly the landing gear shock strut oil level and or air pressure has not been set up in accordance with the maintenance manual. At a guess I would say the nose gear is over pressurised resulting in the centering lock remaining engaged and / or the main gear is under pressure with not enough oil in the leg to get the correct rising spring rate to keep the correct extension of the legs hence the nose stays high and the centering lock stays engaged.
The only answer is to jack the whole aircraft up and do an oil air service IAW the MM. Robin are very clear as to the oil quantity and air pressure required for EACH aircraft variant so a -180 has very different settings to a -120.
The aircraft needs to return to the maintenance hangar before there is an accident involving the aircraft departing the runway side, I once saw a DR400 depart the runway at LFAT, it hit the PAPI lights and the leaking fuel caught fire destroying the aircraft, I offered the pilot a lift back to the UK and during the conversation he reported exactly the same symptoms as detailed above by Paul M.
It is important that this aircraft is not flown until this defect is resolved.