We currently don't support per-level navigation agent radius tweaking. It's done via project setting's Navigation System -> Supported Agents
Show Navigation appears to fail if the Agent Radius is 40 or higher
Expected: The navigation would show up when using the console command "Show Navigation"
Result: The Nave mesh does not show when using the command "Show Navigation"
Head over to the existing Questions & Answers thread and let us know what's up.