Can't segment on Browser = None (bots)

Recently half of our traffic on some pages is caused by web scrapers. We recognize these visitors because they retrieve internet speeds on our website and have "None" as a browser. 

However, when I try to make a segment on this traffic (by segmenting on Browser = "None" or Browser does not exist), I get 0 results. Even when I use the default "Create segment from selection" and place the segment right below a line with "Browser = None" I still get 0 results. 

How can I make a segment for this?