```google/pegasus-cnn_dailymail``` generates blank files
I am working on generating summaries using SOTA models. Recently I am using pegasus-related models to generate results. It surprises me thatgoogle/pegasus-xsumreturns the perfect results whilegoogle/pegasus-cnn_dailymailreturns very bad performance.I am running the code fromtransformers/examples/legacy/seq2seq at master · huggingface/transformers · GitHub, and my transformers’ version is 4.2.0. The detailed implementation is:python -m torch.distributed.launch --nproc_per_node=3  run_distributed_eval.py \
    --model_name google/pegasus-cnn_dailymail  \
    --save_dir $OUTPUT_DIR \
    --data_dir $DATA_DIR \
    --bs 32 \
    --fp16The performance fromgoogle/pegasus-xsum:{'rouge1': 47.0271, 'rouge2': 24.4924, 'rougeL': 39.2529}The performance fromgoogle/pegasus-cnn_dailymail:{'rouge1': 0.1602, 'rouge2': 0.084, 'rougeL': 0.1134}I also check thetest_generations.txtfile to try to figure out the reasons for abnormal low ROUGE score. It turns out most of the lines are blank. Does anyone meet similar problems when trying to generate summaries usinggoogle/pegasus-cnn_dailymail?