How could it be missing? There is no reason at all.

The young woman noticed that her son wasn't in place and went to Guan Yu to remind the young woman to look in Mickey's direction for only about five seconds.

In such a short time, even if his son leaves Mickey, it's impossible to run far. It's not difficult to find him. Besides, according to Guan Yu's observation of the little boy just now, he finds that he doesn't love Mickey in general. Otherwise, it's impossible for Mickey to lead him. So Guan Yu's inference is that her son can't leave Mickey's side.

But now the problem is that...