I tried creating a topic modelling using pyldavis gensim library and now the clusters are made. I have one question about the same.Clusters made are cut from the edges. Is there a problem or its fine?

A similar sample graph would be: https://miro.medium.com/max/1086/1*80r1wLMCyK615S6-j3TLWQ.png. Also, is there a citation that can back the result?

Thanks I tried pyldavis for the same.