Identity Collector version 81.023.
I had a couple of times times the occurence that modifying anything in the Global Filter would stall the agent, even for something as simple as adding an account or subnet in the exclusion list.
It wouldn't show any new events and send anything to the FW. Hits would ramp up as soon as I removed the change done in the global filter and identities would reappear in the gateways.
Creating a gateway-specific filter does not show this behaviour. I don't find specific caveats for the Global Filter in the documentation so I wonder if I would be missing something there.