Checkboxes_detection with python_boxdetect package

I am trying to detect checkboxes using the boxdetect package (python), the script from (https://pypi.org/project/boxdetect/) works very well for unfilled document (i.e. it detects all unticked checkboxes from an empty form, howevere when I am trying to apply this script on a filled form (same document but contains ticked/non ticked checkboxes) it doesnot reqognize all checkboxed.(the size of the emapty form image= the size of the filled form image) does anybody have an idea/or other module suggestion to detect checkboxes with python #I used following script: (two output images are attached)

    file_name = "checked_new.png"

    cfg = config.PipelinesConfig()

    cfg.width_range = (10,60)
    cfg.height_range = (10,55)

    cfg.scaling_factors = [1.3]

    cfg.wh_ratio_range = (0.3, 2)

) cfg.group_size_range = (1, 1)

    cfg.dilation_iterations = 0

    from boxdetect.pipelines import get_boxes

    rects, grouping_rects, image, output_image = get_boxes(file_name, cfg=cfg, plot=False)