Solved, I think. I removed via Brew, and re-installed. Seems to be working now.
I'm using brew to run Packetbeat as a service. If I do this, nothing gets added to the ES index.
If I interactively run it (sudo packetbeat -e), everything logs fine.
What did I miss?
Thanks for any help anyone can provide!
macOS Catalina 10.15.4