"TsinghuaAI/CPM-Generate" model performance

Hi all, I am using TsinghuaAI’s CPM model “TsinghuaAI/CPM-Generate” in a zero-shot fashion for keyword extraction on some smaller Chinese dataset. Surprisingly I am finding its performance much poorer as compared to e.g. Sentence Transformers’ “paraphrase-multilingual-MiniLM-L12-v2” . Has anyone had some similar experience so far? Many thanks in advance!