Can't ping other devices after starting ROS2 processes with Discovery Server

[sterlingm]

I'm following the Turtlebot 4 documentation to set up a Discovery server configuration. I need to use a discovery server setup because the robot's mobile base only connects to 2.4GHz band, but my university only allows 5GHz bands.

The Raspberry Pi 4 is meant to be the server. My laptop has the ROS_DISCOVERY_SERVER environment variable defined as <RaspberryPI-IP>:11811. The Raspberry Pi has ROS_DISCOVERY_SERVER defined as 127.0.0.1:11811 since it is the one hosting the server. I have tried using its IP on the network, but I get the same behavior. The ROS_DOMAIN_ID variables on both the Pi and my laptop are the same.

The network we are using is a WLAN provided by a simple retail router, and it has no Internet access. There are only about 3-4 devices connected at any one time.

When I start something ROS 2 related, such as "ros2 run teleop_twist_keyboard teleop_twist_keyboard" on my laptop, the laptop loses connection with the network. Further, other devices on the network can no longer ping each other. It's like the whole network goes down. Sometimes everything recovers after 30-60 seconds, but sometimes it does not and I have to restart my laptop and/or the Turtlebot's Pi.

I guess something is going wrong with the discovery process? Is there a way for me to see more information about discovery when I launch a ROS 2 node (maybe some kind of verbose setting I can toggle)? Can I see if the messages sent to other devices on the network are received? Can I see how many messages a node is sending for discovery and/or when it stops sending messages?

Edit: It seems to only be happening when the Turtlebot's Raspberry Pi 4 is on the network. If I turn off the robot and change the ROS_DISCOVERY_URI to be a different device, then I can start ROS nodes and everything seems to be working fine. However, once I turn the robot back on and start ROS2 nodes, then all devices seem to lose connection to the network (which sometimes seems to resolve itself after a minute). This happens when the PI is on the network regardless of which device is set to be the discovery server.