In all the Angular projects using Material I have worked on in the past, VS Code can never find the name of the module I try to import.
If I try to add, for example, the MatButtonModule to the list of import, VS Code says Cannot find name 'MatButtonModule' and the quick action context doesn't propose to import it.
Up until now, I always had to write the import line manually.
I recently noticed I have the same issue with all their harnesses from the testing cdk.
The baseURL in my tsconfig file is /src and VSCode usually has no issue with any other import. It also work for material components.