Not all Feature Points are displayed (with ORB)

I have the problem that not all feature points are displayed in one image. I use the ORB algorithm with OpenCV-JS for the FeaturePoint “detection”.
The figure shows my problem: The feature points that are on the edge are not displayed or detected.
Here is my pseudo-source code:
processImage(imgSrc, tmp) {

    const im1 = cv.imread(imgSrc);
    let im1Gray = new cv.Mat();
    cv.cvtColor(im1, im1Gray, cv.COLOR_BGRA2GRAY);
    let keypoints1 = new cv.KeyPointVector();

    let descriptors1 = new cv.Mat();
    var X = new cv.ORB(100000);

    X.detectAndCompute(im1Gray, new cv.Mat(), keypoints1, descriptors1);
    tmp = keypoints1.size()
    let keypoints1_img = new cv.Mat();
    for (let index = 0; index < keypoints1_img.size(); index++) {
    cv.drawKeypoints(im1Gray, keypoints1, keypoints1_img, color);
    cv.imshow(this.grayImgRef.current, keypoints1_img);