It sounds as though you used the "Insert Item Beside" button, shown to the right of existing form items, to add the new field. I'll provide an example to illustrate how to add a new field below an existing form item. Given the following form, let's say I want to add a second text field below the "Name" field.
First I would select the form item above which I want to add the new field, in this case the "Billing Address" item. I would then click the "Insert Item Above" button, highlighted in red below, to expand the inline palette.
I would then select the type of form item that I want to add.
Regarding the drag/drop issue, try dragging the field toward the left edge of the page. You should see an insertion marker at the left margin showing that the item will be positioned on a new line, as shown below.
Let me know if you continue to have trouble moving form items.
Thank you for your help.
I'm afraid I didn't explain my problem correctly.
I have a text box, which contains several lines of text, with 2 buttons. One allows to insert an item above, the other allows inserting an item beside.
I click on the "insert item beside" button.
Then I insert a text field (or whatever kind of field).
This text field is positionned beside the text box (on the right).
Now I want to add an item (another text field) below the previous text field. That means that this text field should be positionned beside the text box, and below the previous text field.
I can't remember how to do that. If I click on the first text field, and choose "add an item above", the new item is positionned above the text box, not above the text field.
I can send you the file, if you want.
Sorry for my poor english.