If the edit section / row / module is not showing the titles as per the image, then you have probably set you H3 tag to be white text.

 

 

To fix this either in the theme stylesheet or in the divi theme css settings, set the following:

//You can set the color the to be any you like other than white (#ffffff)   tongue-out

.et-fb-form__toggle-title h3{
color: #000000 !important;
}