Hi there,
I'm using your multiselect combobox together with WPF.UI (https://github.com/lepoco/wpfui) , but it looks like they don't harmonize well together.
The box is pretty narrow, just like in issue #109 .

The combobox itself is correct when sniffing with snoop:

The issue seems to be in the ToggleButton

I am using 1.0.103 via nuget.