Bug at TimePicker when IsClockVisible="False"

[bodkia22]

When I use TimePicker and want to get rid of the clock by using IsClockVisible="False". TimePicker is not working at all.

Just create TimePicker:
<mah:TimePicker IsClockVisible="False" Width="120" Height="22"/>

Expected result:
TimePicker should be shown without a big clock.

MahApps.Metro version: v2.4.3 and v2.4.4 have this bug either
Win10
Visual Studio: 2017
Target Framework: .Net Framework v4.7.2