The react custom component cannot display what is added later

intra-component code:
clipboard.png

:
clipboard.png

can only display the content in the original PageTitle component, but not the content in the div added later.
browser Console does not report an error and compiles normally, but it cannot be displayed, and there is no div in the source code.
A novice asks everyone for help. What may be the cause of this? Or am I using it wrong? Thank you very much, bosses.

Mar.20,2021

I don't understand the relationship between PageTitle and added goods.

if the two structures are juxtaposed, you can just write < PageTitle title= "item list" / > instead of writing a closed label separately.

if it is an inclusion relationship, write {this.props.children}

in the return of PageTitle .

like this, this.props.children is what you wrap in PageTitle

.
// PageTitle
render(){
    return(
        <section >
            <h1></h1>
            <ol></ol>
            {this.props.children}
        <section />
    )
}
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