I'm using Immutables to generate builder source files. The oracle.oracle-java VSCode extension appears to work correctly for discovering and running your project's annotation processors. However, the language server doesn't appear to work correctly on these generated source files:
The broken import statements from the above screenshot are Maven dependencies, and the source file does compile when I manually run mvn compile. It seems the language server is not examining the project's dependencies and local project classes for discovering the import declarations. It does, however, find the import declarations from the standard Java library.