DateTimeEditBox What the heck am I doing wrong

Not sure of the Product Version or build number. They do not show up in the 'ActiproSoftware.Editors.Wpf' properties. The runtime version is : v4.0.30319 and the version is 17.1.650.0. My problem is pretty basic. My Xaml is as follows:

xmlns:editors="http://schemas.actiprosoftware.com/winfx/xaml/editors"
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
xmlns:command="http://www.galasoft.ch/mvvmlight"

            <editors:DateTimeEditBox x:Name="StartTime"
                                 Minimum="{Binding StartMinimum, Mode=OneWay}"
                                 Maximum="{Binding DateMaximum, Mode=OneWay}"
                                 Value="{Binding StartDateTime, Mode=TwoWay}"
                                 MinWidth="150">
            <i:Interaction.Triggers>
                <i:EventTrigger EventName="ValueChanged">
                    <command:EventToCommand Command="{Binding StartDateChangedCommand}"
                                            PassEventArgsToCommand="False" />
                </i:EventTrigger>
            </i:Interaction.Triggers>

        </editors:DateTimeEditBox>

The code just has 3 DateTime Properties: StartDateTime, StartMinimum, DateMaximum.

I would assume, Value would bind to the StartDateTime and it does show the initial value in the controll correctly but when you click for the dropdown it has the Maximum value selected and selecting a different value does not update either the textbox or the StartDateTime property. I have tried playing with other properties like 'CommitTriggers' and 'IsNullAllowed'. As you can see, I also tried using interactive triggers with this code

Oddly it did actually work briefly twice, like I imagined it should: Updating both the StartDateTime property and calling the StartDateChangedCommand but restarting the app, brought back the same old behavior. I am using Visual Studio 2017 Professional version 15.9.11 if that helps. 

Another issue: Before I simplified the problem, I was originally using 2 DateTimeEditBoxes and thought they might be interfering with each other since in your ProductSamples browser there is a checkbox for the control that reads "Can retain time (useful when also binding a seperate TimeEditBox)" Your source code however does not have this entry so I have no idea what property it is or if it exists at all. There is no 'CanRetainTime' or 'RetainTime' value.

On a side note your ProductSample source code is not very helpful. I would prefer it if you set up MVVM classes to bind to your controls since I imagine that is how most people code.