MAUT AppShell top blue bar

I’m trying to use a AppShell page to visualize 2 pages. I don’t want anything in the upper part of the page.. My code is the following

<?xml version="1.0" encoding="UTF-8" ?>
<Shell
    x:Class="MAUI_Diet_002.AppShell"
    xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
    xmlns:local="clr-namespace:MAUI_Diet_002"
    Shell.FlyoutBehavior="Disabled"
    Shell.TabBarBackgroundColor="{StaticResource DietMain}"
    Shell.BackgroundColor="Transparent"
    Shell.NavBarIsVisible="False"
    Shell.FlyoutItemIsVisible="False">

    <TabBar>
        <Tab Title="Names">
            <ShellContent ContentTemplate="{DataTemplate local:SearchByName}" />
        </Tab>
        <Tab Title="Categories">
            <ShellContent ContentTemplate="{DataTemplate local:SearchByCategory}" />
        </Tab>
    </TabBar>
    
    
</Shell>

The first time I go on the Names page it looks like this.

But if I go to Categories page (that runs perfectly) and I come back to Names a top blue bar appears. And from that moment on it’s not possible to eliminate it.

I have assigned NavBarIsVisible=False. I have also tryed to assign a color to the NavigationBar to see if it was really a NavigationBar, but the result was always the same

First question: what is the blue bar?  Not the Navigation, I suppose

Second: How can I remove it definitively?