I am using ArcGIS Pro 2.7.1 and I am trying to create a new grid in a layout showing Township and Range. When I format the grid and go to the "Components" tap to choose the edges under the "Visible" section, I am unable to choose an edge. Everything there is greyed out and I get this pop-up text when hovering over the numbers:
The source polygon layer is located in the same Feature Dataset that the other layers are in and all of the coordinate systems match. Not sure what the issue is here.
It looks like you still have All selected for the Edges. You'll need to click Selected before those controls are enabled. When the All option is highlighted everything you do applies to all edges, you can't selected individual edges until Selected is chosen.
Hmmm. I can't reproduce with my own township and range data. As long as Selected is chosen I can click individual edges. This sounds like a bug. Can you reach out to Technical Support? https://support.esri.com/en/contact-tech-support They can troubleshoot the issue and enter a bug for the development team.