Make Divi mobile dropdown menu fullwidth
To make Divi mobile menu fixed go to Divi -> Theme Customizer -> Mobile Menu Customizer -> Menu Settings and find the MAKE MENU FULLWIDTH setting.
Set it to Yes and then select thedevice types you want the dropdown menu to be fullwidth on: Tablet and/or Phone.
Click the Publish button to save your changes.
This feature is available for the Default, Centered and Centered Inline Logo header formats.