Issue with SumStats and tcpdump filters?

I am writing a zeek script similar to one of the samples, and it works fine when I don’t specify a tcpdump filter but not when I do. My filter looks something like tcp and dst host 1.2.3.4 and dst port 80 where 1.2.3.4 is an IP address that is on the interface zeek is listening on, but even simpler filters don’t work. Before I dig into the code, is there a reason this doesn’t work?