A bug or a issue has been spotted in realms causing them to crash after they reach 1 minute or 20 minutes after a backup. When the crash happens nothing happens, no mobs move, no commands run, block no longer function correctly, items no longer drop, and you can't die. Your character will still be in the realm, however it will be like that till you disconnect and wait for the file to refresh. Then the file goes back to the last save causing players to lose data. This is not a player based issue as its been tested with 10 players on a realm and they all report the same thing at the same time during the crash.