Submit empty fields (to FluentCRM)

Hello friends!

I try to explain my problem easily first and then in detail what I want to achieve.

My problem:
I recognized, that when a user in a form is not filling out the field then nothing is submitted to the form entry data table and then of course as well not to the created contact in FluentCRM.
That means in detail if a user has already one time submitted the form and data was written to the field, the contact in FluentCRM is set with this value. If the user calls the same form a second time and changes the value of the same field, the changed value is submitted to the form entry table and the contact in FluentCRM is updated. But when the user leaves the same field empty for the second time when he submits the form, it’s just considered as an “empty field” and the contact in FluentCRM is not updated with the empty value.
Do I have any possibility to set every empty field in the form to the value “null” when submitting the form? And would “null” update the contact in FluentCRM with an empty value then?

What I want to do:
I want to build up a site where a user can see and update his own data. I’m offering education for a paragliding license and my student, when he starts with the education should fill out a form with his data the first time. The form should offer checkboxes where the student can check that he did “the first practice with a paraglider”. Ongoing the form will offer checkboxes for the complete education. For example a next checkbox that the student “made his first single start” or “flew his first 360 degree circle”. I came already that far, that I integrated my form with fluentCRM and that I’m saving the data as a contact.
As well I’m calling the default value of the checkbox from already existing contacts from fluentCRM and it works. Then I was playing and thinking scenarios and recognized that if a student is ticking a checkbox one time to “checked” and submits, he can never update it to unchecked again when he uses the form the next time. This is, because if the checkbox is “unchecked” it’s considered as an empty value. In the form entry data table the value is empty and when i show empty fields, i can find my checkbox there. With this submission the custom field in the contact stays like it is with the value checked. Next time calling the form and getting the default value again from fluentCRM the checkbox is checked again. Only thing what i can do then in the dashboard is to go to the contact in fluentCRM and update the contact as an admin.

Is it understandable? I could make screenshots and put it to my website and explain the whole thing again there if needed?

Thanks in advance for any advice!

Emanuel

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