Hi there,
in Appearance > GeneratePress there are two modules:
Elements
and Disable Elements
Make sure both are Activated.
Option 1: The Disable Elements adds a Meta Box that includes the option to disable the Content Title
https://docs.generatepress.com/article/disable-elements-overview/
You can use this to remove it on a page by page basis.
Option 2: Create a Layout Element in Appearance > Elements:
https://docs.generatepress.com/article/layout-element-overview/
With this you can Disable Elements or set other layout options, and use Element Display Rules for where to apply it eg. Pages > All Pages