Pushing 'G' makes the navmesh bounds volume disappear?

Mostly what the title says. I have a project that I've been working for a while and decided to add AI to it finally.

My test map has gotten pretty huge, so I deleted the navmesh bounds volume and Recastnavmeshdefault and re-added a navmesh bounds volume. Because my ai moveto was failing. Now it refuses to show the navmesh bounds in green when I hit G. The whole box, other objects scene roots, the arrows to move it, all just disappear.

I have the same thing working in a clean project. But I don't know what happened to this one or how to re-enable this. Starting over/importing the code to a new project might just break it like this again.

Any suggestions at all would be really appreciated. Thank you.