On post update, all hidden fields on my form get wiped of their previous value

Hello,

I have a public facing form that shows certain fields for the user to fill in which then gets saved and made into a post when they submit the form. This then gets displayed in an admin dashboard area, where they can set the 'status' of the form and associated post.

The problem I'm having is I conditionally hide all the public fields in the admin area as they only need to see the status field, but this seems to wipe the hidden fields value on submit, and only sets the 'status' value (which is the only visible field for the admin). I have tested this by showing another public field in the admin area and then updating the status, this lead to the visible fields value being kept but all the hidden ones getting wiped.

I'm just wondering if this is intentional & if you can think of anything i can do to keep the values of the hidden fields?

Here's the short code I'm using for the update form incase it is helpful, it is in the single posts page template;

<?php echo do_shortcode('[gravityform id="16" field_values="submission_type=Updated" update); ?>

Thanks in advance, Harry.