property editor prevalue formatting

Hello,

I am in the process of creating updated v8 version of my old similarity package. I am having a weird issue on my prevalue editor.

My prevalue editor view markup looks like:

<div class="umb-property-editor umb-select" ng-controller="Similarity.DocTypeController as vm">

<select ng-change="docTypeChange(vm.selectedDocTypes)" ng-model="vm.selectedDocTypes" class="umb-editor umb-dropdown" ng-options="docType.documentTypeId as docType.documentTypeAlias for docType in vm.docTypes" multiple>             
</select></div>

The view renders in the back office and the select is populated with data however its position is off the top of the page. See screen shot below:

Anyone any ideas? I also have a checkbox list and multi select box they also appear off the page. The in built views for textbox renders and appears fine.