Redirect_uri is missing from authentication page after failed auth

Probably a simple issue but my research has failed to expose the solution. Here is the setup …

I’m using keycloak-angular in an Angular 10 application, using silent redirect authentication checking

Here is the problem:
User navigates to url and gets redirected to login.
Login url is https://[keycloak endpoint]/realms/[realm]/protocol/openid-connect/auth?client_id=[client]&redirect_uri=[correct redirect uri]
When user login fails … the browser redirects to:
https://[keycloak endpoint]/realms/[realm]/login-actions/authenticate?execution=[some uuid]&client_id=[client]&tab_id=[some id]

The problem (at least as my rookie eyes see it) is that the redirect_uri is missing. This is not an issue on the surface because if I then subsequently succeed to log in, I’m properly redirected to the original redirect_uri. My problem is that I have some custom script in my login theme that relies on the redirect_uri value to display the correct logo and color scheme.

What I’m hoping to learn:
Is there a way to preserve the redirect_uri, or is there some other way to detect where the login will redirect after a successful login so I can preserve the theme scheme?