I think the issue is best illustrated using a picture:

So my doc has multiple spans with label LOC or ORG. I would expect the selector component here only show me these two values. However, looking at the code for visualize_ner() I see we do not remove duplicates from labels for different spans. I am not sure if this has been there all along or something changed with recent versions of streamlit.

I am using the following version of the packages:

spacy-streamlit           1.0.4
streamlit                 1.12.0