Lead Page Preview Showing ‘Array’ for Checkbox Entry

I have setup the plugin to ‘save lead’. When I click onto ‘Leads’ in the preview area it shows all fields correctly, apart from a checkbox option I have in my form. Under the preview this just shows the word ‘array’ rather than the checkbox option. If I click ‘Edit’ on the lead it will show the correct wording from the checkbox option so it is only on the leads page preview. How can I resolve this? Thank you.