Retinanet percent_boxes_matched_with_anchor is 0 when using example code

[Khrisvana]

When attempting to train a simple RetinaNet model using keras_cv, I encountered the message percent_boxes_matched_with_anchor: 0 during training.

Here is the code I used to reproduce the issue:

import numpy as np
import tensorflow as tf
import keras_cv
from tensorflow import keras

images = np.ones((1, 512, 512, 3))

labels = {
    "boxes": tf.cast([
        [
            [0, 0, 100, 100],
            [100, 100, 200, 200],
            [300, 300, 100, 100],
        ]
    ], dtype=tf.float32),
    "classes": tf.cast([[0, 0, 0]], dtype=tf.float32),
}

model = keras_cv.models.RetinaNet(
    num_classes=1,
    bounding_box_format="xywh",
    backbone=keras_cv.models.ResNet50Backbone.from_preset("resnet50_imagenet")
)

model(images)
model.predict(images)

model.compile(
    classification_loss="focal",
    box_loss="smoothl1",
    optimizer=keras.optimizers.SGD(global_clipnorm=10.0),
    jit_compile=False,
)

model.fit(images, labels, epochs=10)

the log resulting in percent_boxes_matched_with_anchor: 0, from epoch 1 -> to 10. Is there something i missed?

im using tensorflow: 2.15, keras: 2.15, keras_cv: 0.9.0