It sounds like you might be describing the movie “Impostor” from 2001, directed by Gary Fleder and based on a short story by Philip K. Dick. The movie stars Gary Sinise as Spencer Olham, an engineer and family man who is accused of being an alien spy and is hunted by government agents. As he tries to clear his name and prove his humanity, he discovers that he is actually a clone with implanted memories, created by the government to assassinate a key scientist. Along the way, he meets Maya (Madeleine Stowe), a woman who helps him uncover the truth about his identity and his mission. Does that sound like the movie you were thinking of?
No, but good try. I kept adding information to my request of AI ChatGPT, over and over, and it came up with many recent movie titles but none remotely resembled what I was seeking. I gave up after a dozen attempts and gave reviews regarding the inaccuracy. It seems that ChatGPT doesn't know how to say "I give up, I don't know!".
As for the movie I'm seeking, it was probably over 40 years old or more. The amnesiac man is being hunted by the government that wants to destroy him (thinking he is a terrorist), and is befriended by a human man. Together, they not only find out that he is a robot, but gradually find clues to a secret lair where they find hundreds of dead clone robots and equipment. Only then does he discover that over thousands of years their task was to guide humanity and keep it from destroying itself. Also that each robot would build its successor to carry on the work over millennia. The robot then regains his memories and has many computer displays at his disposal to watch over humanity.