Thank you @Xavier for the tip - from the network tab I was able to confirm there was an error on topo.json fetch that came from my middleware requiring authorization to access that path and my NextAuth authorized callback not approving the path.

More specifically, my middleware used a regex pattern that allowed for .png assets in the public folder to be accessed without approval, but not .json - hence why I was able to access the logo without issue.

Since the map feature is accessed after login, I decided to add the /topo.json path to one of the approved paths for a logged in user in my auth.config.ts., rather than add the topo.json to auto-approved paths in the middleware.