it's not that reason. when you upgrade, the system will prompt you what tasks can be done at this level, but there is no prompt, which means that there are no tasks to be done at this level! At 22: 11 and 23: 11, the system does not prompt for tasks, because there is no task at level 23. Level 22 is the task of "Tiger Hunter" and "East Gate Guard"; Level 23 has no mission.