dying when loading into realms

So two times now I have logged into the server after logging off in my friends realm only to be greeted by a death screen. The first time I logged in I had no idea how I died, and all of my stuff was gone as my grave somehow despawned. The second time I luckily had a totem of keeping, however, I lost my levels and still don't know how I ended up dying. I ensure I log out every single time and close the Minecraft tab, and would really like to stop being greeted to a death screen.