Needing assistance with passenger door central locking not working properly. – Honda CRV

Please can you let us know what the situation is with our central locking on the passenger door not working. Central locking locks, then slowly unlocks itself. The locking system on that door has been “cleaned and fixed” with it working only temporarily then starts unlocking on its own again. What are the options to fix this please and what are the costs involved. Please use whatsapp only as communication. Thank you