TextBox Problem until Update!?!?!

Question

Hi!
I have a Problem with TextBoxes after the last Update unter VS 2019!?

Under the TextBox where Now an underline and the Size of die Field!?
Normal there is nothing!
It Show on Debugging and on Realtime(Runtime) Mode...
How can i swich this of?
Have anyone an ides?

...  
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"  
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"  
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"   
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"   
  
             xmlns:local="clr-namespace:Test4"  
  
             xmlns:commonWPF="clr-namespace:WpfTextBoxNumeric"          
             xmlns:materialDesign="http://materialdesigninxaml.net/winfx/xaml/themes"          
             mc:Ignorable="d"   
             d:DesignHeight="550"   
             d:DesignWidth="800">  
      
...  
                <TextBox x:Name="TextBoxName" Height="24" Canvas.Top="58" Canvas.Left="166" TextWrapping="Wrap"  Width="220" FontWeight="Bold" MaxLength="20" TabIndex="1002" FontFamily="Tahoma" VerticalContentAlignment="Center" />  
...