He did say intrusion detection so that's probably it. That, and if you're using any kind of complicated firewall rules, those aren't HW accelerated like enterprise gear, so throughput tanks.

This is worse with the older devices.

For example: https://www.youtube.com/watch?v=p4yKf044meY

https://community.ui.com/questions/UniFi-Gateway-Intrusion-D...