The following Game loop doesn’t seem to work, as the print commands both only output 0

public static void run() {
    int frames = 0;
    long timePerFrameInNano = 1000000000/TARGETFPS; //TARGETFPS is set to 60
    long lastUpdate = System.nanoTime();
    long timer = System.nanoTime();
    
    while(true) {
        if(System.nanoTime()-lastUpdate >= timePerFrameInNano) { //If enough time passed
            frames++; // count frames to check FPS after each second
            lastUpdate = System.nanoTime();
            update();
            render();
            System.out.println(frames);
        }
        
        if(timer >= 1000000000) { //After 1s, update the FPS
            timer = System.nanoTime(); //Reset 1s timer
            fps = frames; //All the frames counted afetr 1s should show me the current fps
            System.out.println(fps);
            frames = 0;
        }
    }
}

Instead of the expected 60FPS it only shows me 0. I’ve been going back and forth in debug mode and couldn’t figure out what’s wrong.