What does it mean when it says "activity Heartbeat timeout" in one of my AI agent chats? Is it saying that because I had the same AI agent open in a different project as well, and when I switched back to the original project I was using the agent for, it hadn't sensed a "pulse" for a while so when I sent a message, it gave it a timeout? When I refreshed the original project after receiving that message, it responded to my prompt. My assumption is that this likely happened due to the idle period, and the refresh brought it back to life in a sense?