Pending component doesn't work on root route

[geoff-harper]

Which project does this relate to?

Router

Describe the bug

I've noticed the pending component doesn't stay mounted if it's on the __root route. It seems like it does quickly render but doesn't stay until the __root loader method is finished, instead it instantly unmounts

Your Example Website or App

https://codesandbox.io/p/devbox/epic-shape-z676nh

Steps to Reproduce the Bug or Issue

1. Verify that you see a green box on first load to verify that non __root pending component works
2. Go to src\routes\index.tsx and comment out the pending component and loader
3. Go to src\routes\__root.tsx and uncomment the same code from previous file
4. Verify that the green box does not appear after refreshing window

Expected behavior

I expect to see the green box upon loading after the 4th repro step. I've left a red box as the router's default pending component to show that does seem to be working normally in all relevant cases

Screenshots or Videos

No response

Platform

• Version: 1.57.8

Additional context

No response