I have a web map with unique values symbology created in ArcGIS Pro containing some symbol classes which have been grouped to reduce the number of types of symbols in my map. I did this by grouping feature types and adjusting the corresponding label to include everything in the group; for instance grouping various types of bioretentions and bioswales together under one "Bioretention / Bioswale" label. The problem is that when I view the legend in my web map, it contains an identical entry for each individual feature type in that group, as shown here:

Is there a way to remove the redundant entries from my legend? It is incredibly frustrating that there is no apparent way to do this in Map Viewer.