UWP: how to log the display events of a PivotItem - xaml

Question

I encounter a "latency" problem on a screen that contains a Pivot and 5 PivotItems. These problem only occurs the first time than the 3rd and the 4th PivotItems are displayed. When I come back to these PivotItems, or if I select others PivotItems I don't meet the same "latency"...
I tried to understand where come this problem, so I've added some events on the PivotItems: Loaded, Loading and GotFocus. In my logs, I see that Loaded and Loading are well called after the page is displayed, but GotFocus is only called if an item in the PivotItem is focused.
I also use the SelectedIndex on the Pivot, but this doesn't help me to understand why I meet latencies with 2 PivotItems...
All the datas of the displayed form are loaded from a SQLite database through the LoadDatas() method: so when I browse the PivotItems, the datas are already loaded. In my logs, I see that Loading or Loaded are well called after the loading of the datas in the Constructor:
11.07.18.615885 : HomeViewModel - OpenForm()
11.07.18.662764 : DetailsViewModel - Ctor() - start
11.07.18.662764 : DetailsViewModel - LoadDatas() - start
11.07.18.803396 : DetailsViewModel - LoadDatas() - end
11.07.18.803396 : DetailsViewModel - Ctor() - end
11.07.19.053413 : DetailsPage - PivotItem_Loading() - DetailsGeneralPivotItem
11.07.19.053413 : DetailsPage - PivotItem_Loading() - DetailsMachinePivotItem
11.07.19.069042 : DetailsPage - PivotItem_Loading() - DetailsComponentPivotItem
11.07.19.069042 : DetailsPage - PivotItem_Loading() - DetailsFormPartsPivotItem
11.07.19.069042 : DetailsPage - PivotItem_Loading() - DetailsFeedbacksPivotItem
11.07.19.287811 : DetailsPage - PivotItem_Loaded() - DetailsGeneralPivotItem
11.07.19.287811 : DetailsPage - PivotItem_Loaded() - DetailsMachinePivotItem
11.07.19.287811 : DetailsPage - PivotItem_Loaded() - DetailsComponentPivotItem
11.07.19.303432 : DetailsPage - PivotItem_Loaded() - DetailsFormPartsPivotItem
11.07.19.303432 : DetailsPage - PivotItem_Loaded() - DetailsFeedbacksPivotItem
The XAML of the 3rd PivotItem, which is concerned by the latency problem, looks like this:
<Pivot x:Name="Pivot"
SelectedIndex="{Binding SelectedIndexPivot, Mode=TwoWay}"
Opacity="{Binding IsBusy, Converter={StaticResource ActivityToOpacityConverter}}"
IsEnabled="{Binding IsBusy, Converter={StaticResource InvertedBoolConverter}}">
<!-- 1. General / 2. Machine -->
...
<!-- 3. Component -->
<PivotItem x:Uid="DetailsComponentPivotItem"
x:Name="DetailsComponentPivotItem"
Loaded="PivotItem_Loaded"
Loading="PivotItem_Loading">
<ScrollViewer VerticalScrollBarVisibility="Hidden"
VerticalScrollMode="Auto">
<StackPanel>
...
<Grid Grid.Row="0">
...
<!-- Component Order -->
<StackPanel Orientation="Vertical" Grid.Row="0" Grid.Column="0" Margin="4,8,20,0" >
<TextBlock x:Uid="DetailsComponentTextBlockComponentOrder" />
<AutoSuggestBox x:Uid="DetailsComponentAsbComponentOrder"
Name="DetailsComponentAsbComponentOrder"
ItemsSource="{x:Bind ViewModel.VComponentOrders}"
DisplayMemberPath="component_order"
TextMemberPath="component_order"
QueryIcon="Find"
Text="{Binding CarForm.component_order, Mode=TwoWay, Converter={StaticResource StringToNullableIntConverter}}"
TextChanged="asbTextChanged"
QuerySubmitted="asbQuerySubmitted"
SuggestionChosen="asbSuggestionChosen" />
</StackPanel>
<!-- Component Order Type -->
<StackPanel Orientation="Vertical" Grid.Row="0" Grid.Column="1" Margin="4,8,20,0" >
<TextBlock x:Uid="DetailsComponentTextBlockComponentOrderType" />
<ComboBox ItemsSource="{x:Bind ViewModel.ComponentOrderType}"
SelectedItem="{Binding SelectedComponentOrderType, Mode=TwoWay}"
HorizontalAlignment="Stretch" />
</StackPanel>
...
<!-- Hours -->
<StackPanel Orientation="Vertical" Grid.Row="1" Grid.Column="2" Margin="4,8,20,0" >
<TextBlock x:Uid="DetailsComponentTextBlockComponentHours" />
<input:SfNumericTextBox FormatString="N0"
Value="{Binding CarForm.component_hour, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
MaximumNumberDecimalDigits="0"
Style="{StaticResource NumericTextBoxStyle}" />
</StackPanel>
</Grid>
...
<Grid Margin="4,8,20,0">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<TextBlock x:Uid="DetailsComponentTextBlockComponentPhotos" Grid.Row="0"/>
<GridView ItemsSource="{x:Bind ViewModel.CarForm.images}"
IsItemClickEnabled="True"
SelectionMode="Single"
Grid.Row="1">
<i:Interaction.Behaviors>
<core:EventTriggerBehavior EventName="ItemClick">
<core:InvokeCommandAction Command="{Binding PhotoItemClickedCommand}" />
</core:EventTriggerBehavior>
</i:Interaction.Behaviors>
<GridView.FooterTemplate>
<DataTemplate>
<CommandBar Background="White">
<CommandBar.Content>
<AppBarButton x:Uid="DetailsComponentButtonAddPhoto"
Icon="Add"
Command="{Binding AddPhotoCommand}" />
</CommandBar.Content>
</CommandBar>
</DataTemplate>
</GridView.FooterTemplate>
</GridView>
</Grid>
</StackPanel>
</ScrollViewer>
</PivotItem>
<!-- 4. Parts / 5. Feedbacks -->
...
</Pivot>
This PivotItem contains a lot of fields:
AutoSuggestBox
TextBox
ComboBox
Syncfusion NumericTextBox
GridView with photos list
I've already tried to migrate from "{Binding ...}" to "{x:Bind ...}" but I encounter problems with some components: ComboBox, Syncfusion NumericTextBox. So I currently mix these 2 bindings in my page.
I've also tried to remove the GridView block, but the latency is always present.
=> Would you have any explanation? Which events are called at the show of a PivotItem? Is there a way to fix this through XAML? (with "x:DeferLoadStrategy" or another way)