nuPickers.DotNetCheckBoxPicker looses content when collapsing archetype item

[cstrijkert]

I have a Umbraco installation with a legacy Archetype v1.12.0. One of the property I've configured on the archetype is of type nuPickers.DotNetCheckBoxPicker (nuPickers v1.7.1),

Now I've the following problem:

• Select some options in the checkboxpicker
• Collapse the archetype, without clicking on Save & Publish.
• Expand the archtype
• Now the selected options are gone

Especially when adding a lot of items at once, this becomes a nightmare for content editors.

I'm not fully sure if the issue is on the Archetype or on the nuPicker. Can you please confirm this behavior and provide me a solution? That would be much appreciated