How to fix production build with amplify-authenticator in Angular 9 project?

I've got a project using Angular 9 that has an <amplify-authenticator> element, and have imported AmplifyUIAngularModule from @aws-amplify/ui-angular in the single module in the project. It runs fine in a dev build, but when I try to do a production build, it fails:

ERROR in src/app/signin/signin.page.html:13:5 - error NG8001: 'amplify-authenticator' is not a known element:
1. If 'amplify-authenticator' is an Angular component, then verify that it is part of this module.
2. If 'amplify-authenticator' is a Web Component then add 'CUSTOM_ELEMENTS_SCHEMA' to the '@NgModule.schemas' of this component to suppress this message.

13     <amplify-authenticator [handleAuthStateChange]="handleAuthStateChange">
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  src/app/signin/signin.page.ts:7:18
    7     templateUrl: 'signin.page.html',
                       ~~~~~~~~~~~~~~~~~~
    Error occurs in the template of component SigninPage.

I'm using the new Amplify UI Components for Angular, so as far as I can tell there's nothing else to import. Any ideas what could be going wrong?

Solution

Please import AmplifyUIAngularModule in the same NgModule that SignPageComponent is declared in.

AOT (Ahead of Time) compiler resolve the NgModules in sequential order.