How to improve Hierarchical Clustering

Hi,

After I trained my model, I wanted to make clusters on similar topic by using visualize_hierarchy but the result is not that great. The topics in each clusters are not really related. Is it because the dimension of the c_tf_idf matrix is so big ? Or is it because I used transformers to fine-tune my topic representation and so there is a high discrepancy between the topic keywords and topic representation that leads to bad Hierarchical Clustering ?

Start with the reported visualize_hierarchy result and the c_tf_idf matrix and transformer-tuned topic representations described in the issue. Reproduce the clustering behavior, then determine whether the cause is the matrix dimensionality or the difference between topic keywords and representations. Done means identifying and documenting a clear cause or a concrete change needed to improve the hierarchy.