Embedded App Nav links and Jumpy jumpy Polaris content

I have a pretty simple App with 4 Navigation links.

When I click link one, I get a transfer to that route in my React App via the router, and all renders fine. But the content is not smooth rendering. It is kinda jumpy jumpy for lack of a better description. It seems to FLASH a little. I am not sure if this is due to the navigation links, or how Polaris is rendering.

Does anyone else use Navigation Links in an embedded App with Polaris and experience this kind of crappy UX?

What is the solution other than not using this particular stack…