Apple Watch not on find my app

I lost my watch for over a month now. I was pretty sure it’s in the house somewhere, but it was dead when I lost it so I didn’t bother to use my find my app to try to find it. I just noticed that it’s no longer listed as a device on my find my app. Wouldn’t it still show up as a device even if it was dead and not connected to WiFi? It’s like it’s been wiped off my phone