WPF Behaviors no longer working with newest NuGets

Question

The app used to work fine, but a few weeks ago we updated hundreds of NuGet packages. We recently discovered that any reference to a WPF Behavior gives the following error:

System.Windows.Markup.XamlParseException: ''Add value to collection of type 'Microsoft.Xaml.Behaviors.BehaviorCollection' threw an exception.' Line number '78' and line position '86'.'

Inner Exception ArgumentException: Cannot add instance of type 'TextBoxInputBehavior' to a collection of type 'BehaviorCollection'. Only items of type 'T' are allowed.

I suspect this is because of a NuGet update, but I don't know which one had caused the error, or which need to be changed. I'm using the latest version for Microsoft.Xaml.Behaviors.Wpf (1.1.31).

I would appreciate advice. Thanks.

Code:

         xmlns:Behaviors="clr-namespace:MyCompany.MyProject"
         xmlns:i="http://schemas.microsoft.com/xaml/behaviors"

            <TextBox Text="...">
                <i:Interaction.Behaviors>
                    <Behaviors:TextBoxInputBehavior InputMode="DecimalInput" JustPositiveDecimalInput="False" RangeMin="-1000000.000" RangeMax="1000000.000" />
                </i:Interaction.Behaviors>
            </TextBox>

//...

using Microsoft.Xaml.Behaviors;
//...
public class TextBoxInputBehavior : Behavior<TextBox>
//...