Why was my app rejected for OAuth implementation errors?

[thinkval]

Hi Team,

So our app was recently rejected due to the following error

1. Must implement Oauth and complete installation without errors. Resolve any issues that are returning errors after authenticating and ensure that your app has implemented OAuth correctly during the install process. Please refer to our OAuth documentation and see this screenshot for additional details. Your app redirects to an error page after clicking "install". See this screenshot for reference.

Clicking on the screenshot gives me the following error

Our app was created from shopify cli just last month so everything should be using latest code/dependencies.

We verified that our app goes through the proper oauth flow when testing it from a development store.

And it redirects back to our app after installation

Let me know if I need to provide more details

Please advise