Image disappearing [closed]

I have 3 buttons with images that I position in the upper right corner of the screen. If I maximize the screen for just one monitor the images appear correctly, but when I maximize for two monitors the first image turns one stroke and the third one disappears.

I took the test by placing the second image for the three buttons and it works perfectly there. Here is an excerpt of the XAML code and the configuration of the images.

Import.png: 512x512, size 81.4 KB.

Chart.png: 128x128, size: 187 KB.

Config.png: 512x512, size 236 KB.

<Grid.ColumnDefinitions>
    <ColumnDefinition Width="0"/>
    <ColumnDefinition Width="*"/>
    <ColumnDefinition Width="0"/>
    <ColumnDefinition Width="auto"/>
    <ColumnDefinition Width="5"/>
    <ColumnDefinition Width="auto"/>
    <ColumnDefinition Width="5"/>
    <ColumnDefinition Width="auto"/>
    <ColumnDefinition Width="0"/>
</Grid.ColumnDefinitions>

<Grid.RowDefinitions>
    <RowDefinition Height="0"/>
    <RowDefinition Height="auto"/>
    <RowDefinition Height="0"/>
    <RowDefinition Height="auto"/>
    <RowDefinition Height="0"/>
    <RowDefinition Height="auto"/>
    <RowDefinition Height="0"/>
</Grid.RowDefinitions>

<Button 
    x:Name="btnAtualizar" 
    Height="25" 
    Width="25" 
    Grid.Column="3"
    Grid.Row="1"
    Click="btnAtualizar_Click"
    Visibility="Visible"
    >

    <Button.Template>
        <ControlTemplate>
            <Image Source="../Images/Import.png"/
        </ControlTemplate>
    </Button.Template>
</Button>

<Button 
    x:Name="btnGrafico" 
    Height="25" 
    Width="25" 
    Grid.Column="5"
    Grid.Row="1"
    Click="btnGrafico_Click"
    Visibility="Visible"
    >

    <Button.Template>
        <ControlTemplate>
            <Image Source="../Images/Chart.png"/
        </ControlTemplate>
    </Button.Template>
</Button>

<Button 
    x:Name="btnGerenciar" 
    Height="25" 
    Width="25"
    Grid.Column="7"
    Grid.Row="1"
    Click="btnGerenciar_Click"
    Visibility="Visible"
    >

    <Button.Template>
        <ControlTemplate>
            <Image Source="../Images/Config.png"/
        </ControlTemplate>
    </Button.Template>
</Button>

I put in the answer that replaces the images with other icons and so it worked, I do not know if the resolution of the images has anything to do, because the problem was in the two of 512x512, but the people below voted to remove the answer. That is to say, they prefer that other people go without the hint of what I did, besides not helping anything, except for the rLinhares that at least started an attempt.

Bacco, Renan, Dvdsamm, Ismael, Sorack, rLinhares