Chat input doesn't fill with active modal

Hello, I am having an issue with my chat21 app.
While having an active modal the chat’s input field does not fill with a selected string. The same function if attached to a list above the chat input works properly. Why is that behavior?
How can I fix it?

chatInput(messageContent){ // Fills chat input with messages

    console.log('I am chatInput and I approve this message!');

    const welcome = 'Welcome, how may I help you?';

    this.messageString = messageContent; // does not fill the chat's input field as should

    console.log(this.messageString); // outputs this.messageString correctly

  }
<ion-content padding>
    <ion-list>
        <button ion-item *ngFor="let message of messages" (click)="dismissModal(); messageChat.chatInput(message.pr_templ_content)">
            {{ message.pr_templ_name }}
        </button>  
        <page-dettaglio-conversazione #messageChat hidden></page-dettaglio-conversazione>
    </ion-list>  
</ion-content>