Steps to reproduce:
- Go to Site's Content & Data > Forms;
- Add a new Form with two different fields that have the same label and then publish it;
- Go the form's URL and submit a new entry;
- Go back to view the entries of that form and click to export them.
Columns of fields don't distinguish the fields with same label from each other as the exported file does by putting their names between parentheses. Also, weirdly, if I choose the label "text" for the fields and the Site's language is Portuguese, Forms translates the title to "Texto".
The title of each column on the View Entries page should have the field's name between parentheses if there's another column with the same title.