You need to take a logical approach to this problem before you go mad spraying WD40 everywhere and causing more problems.
The system:
– Renault card,
– UCH,
– optical presence sensors located in the door handles,
– access aerials integrated in the door handles and the tailgate,
– locking switches integrated in the door handles and the tailgate badge,
– opening element locking motors.
1st the keycard has a transponder and a wireless transmitter go to the boot if the boot locks and unlocks just by the boot buttons then it is safe to say the keycard is fine the boot is less likely to fail due to protection, position and use.
That leaves door aerials, optical presence sensors and door handle button this all can be confirmed using the Renault clip but on logic if the car unlocks putting your hand behind the handle or pulling it, then the handle aerial is good so that's eliminated and the optical sensor should be fine which leaves the button which is checked while locking a silver handle is about £60 new and does both sides at this point take the door handle off split the handle and put contact cleaner into the button directly and test with a multimeter push the button and get a beep on the continuity test pressing the metal button and spraying contact cleaner is the most direct way and confirm reliable working button the optical sensor I will have to check on about removal and cleaning I'll see if it can be done externally or if the door card needs removed.