Multiple groups works, but not with CF7

Hi Danny–

I’m having difficulty in assigning subscribers to specific interest groups within CF7 using checkboxes. It works perfectly fine when I use the standalone newsletter signup outside of CF7 (assigns a new subscriber to the two groups checked), but when I want to add subscribers to the same two lists within contact form 7 using checkboxes, it is unsuccessful.

I want to assign my subscribers to “Test list”, and assign them to “first choice” and “second choice” within the group “Grouping 13”. I generated the code in the “Form Settings”, “add a new field” area and added “mc4wp-” before GROUPINGS. The code I am using is:

<b>Your First Name <font style="color: #5a8d0b">*</font></b><br />
    [text* mc4wp-FNAME] </p>

<p><b>Your Last Name <font style="color: #5a8d0b">*</font></b><br />
    [text* mc4wp-LNAME]

<p><b>Your Email <font style="color: #5a8d0b">*</font></b><br />
    [email* mc4wp-EMAIL] </p>

<p><b>e-Newsletter</b><br /></p>

<label>Select Interests:</label>
    <label>
        <input type="checkbox" name="mc4wp-GROUPINGS[13][]" value="first choice"><span>first choice </span>
    </label>
    <label>
        <input type="checkbox" name="mc4wp-GROUPINGS[13][]" value="second choice"><span>second choice </span>
    </label>
    <label>
        <input type="checkbox" name="mc4wp-GROUPINGS[13][]" value="third choice"><span>third choice </span>
    </label>

<p>[submit "Send"]</p>

I assume when they check off “first choice” and “second choice” that they will be assigned to those two specific “interest groups” (if that is the correct terminology…) but nothing occurs. Just a single normal checkbox works and assigns them to one list within cf7.

Thank you for any help you can offer, it is greatly appreciated! I looked at all other relevant posts regarding interest groups but still no luck.

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