From the error "The value of 'bboxB' is invalid. Expected input to be finite.", it seems like one or more of the groundtruth bounding boxes have NaNs/Inf values. Make sure your groundtruths are valid and non-empty i.e., the values of the bounding boxes are finite, positive, non-fractional, non-NaN and should be within the image boundary with a positive height and width. You should either discard or fix the samples with invalid bounding boxes.