Cannot configure Overall Test Coverage Gadget's Test Environment Section in Confluence

When Inserting or editing Overall Requirement Coverage Gadget Macro in Confluence, Test Environment options are not saved or displayed correctly:

When editing the gadget, this is the result:
Expected Behaviour:

1. Edit Page
2. Edit Gadget
3. Enter Test Environment Name, Drop Down shows available names, Select Name, Name is saved

Actual Behaviour:

1. Edit Page
2. Edit Gadget
3. Enter Test Environment Name, Gadget Configuration Reloads -> not saved