Foundation Form Stacks - Checkbox/MySQL Issue

I have created a form using the Foundation Form stacks. Within it are two checkbox form stacks; one with 7 selections to choose from and the other with 3 (I need the user to have the ability to make multiple selections against each). I have the form putting the data into a MySQL database when the Submit button is pressed. The data from all the other form stacks enter successfully into the database, however, with both checkbox stacks, the MySQL fields just shows the word “Array” rather than the data when I query the database. An email is also sent on submit which appears successfully, and that displays the options selected in the checkbox fields.

Can anyone help?