Every Form Styler module starts with the same question: which of your forms is this? The field is labelled Form, and the dropdown behind it is filled differently in the two builders. That difference is worth knowing when a form you just built is not in the list.
Where the list comes from
In the Divi 5 Visual Builder the plugin registers a single settings item into the builder’s own data when the builder loads, and every form styler reads its own slice of it. Only form plugins that are actually active contribute, and each is detected by looking for a class, a function or a constant that plugin defines, so a plugin that is installed but deactivated adds nothing.
In the Divi 4 builder each module builds its own list from the same source when its settings are opened.
When a form is missing
- Reload the builder. The list is assembled once, when the builder loads. A form created in another tab after that is not in the dropdown until you reload.
- Check the form plugin is active. With it deactivated the module is not registered at all, so the question does not arise: the module is gone too.
- Give the form a title. The list is built from titles, and an untitled draft is impossible to pick out of a dropdown.
- Reopen the module and pick it.
The placeholder difference
The Divi 4 list opens with a Select a form placeholder. That placeholder is deliberately kept out of the Divi 5 payload, because in Divi 5 the first entry in the list is also the field’s default, and defaulting to a placeholder gives you a module pointed at a form that does not exist. So in Divi 5 the dropdown starts at your first real form. Both builders still treat the placeholder value as no form at all, so an old layout that stored it renders nothing rather than erroring.
After you pick
The module stores the form’s identifier, not a copy of the form. Editing the form in its own plugin changes what the module renders, with nothing to resync. Deleting the form leaves the module pointed at something that is gone, so repoint it rather than leaving an empty section on the page.