Select2 dropdown list does not open after second editor openning

Hi

Have a series of select2 field in my editor form.
Everything works find when i open the editor for the first time. But after closing the editor form, and reoppenning it in create or edit mode, the dropdown field is clickable but nothing appear when clicking on it.
I will need to reload the page to get it working again.

{label: "Select type: ",name: "metadata_field_2",type: "select2",opts: {placeholder: "Select a content type",minimumResultsForSearch: 5,multiple: false,closeOnSelect: false,include_hidden: false}, options: generateTypeList(find_type('content[].type'))},

I upgraded from Select2 4.0.6 to 4.0.13 but not better.
I am using Editor 1.9.2

Any suggestions ?
Thanks in advance