Spring boot Webflux router endpoint produces 404 with external server

When using embedded Tomcat (v.10.1.19) server in IntelliJ Ultimate (Build #IU-233.14475.28) the reactive app I realized with Spring boot (v.3.2.3) and webflux dependency works just fine. However,  when deployed on external Tomcat server (v.10.1.20), the app reports http status 404. What I did so far:

• First, I thought it was a problem with my SecurityWebFilterChain but even stripping the project of all Security components it produces the same result. 
• I double-checked the context, used all sorts of deployment approaches, renamed and reconfigured my endpoints to the bare minimum. 
• I checked for related answers on StackOverflow and found this older post here https://intellij-support.jetbrains.com/hc/en-us/community/posts/360000021519-Tomcat-deployment-and-use-in-IDEA-works-but-404-when-deployed-to-server . The changes in the stack and my specific requirment make me think that this might be due to some different cause. 

I'd be glad to understand the reason, could anyone help with analysis? 

Router

@Configuration
@EnableWebFlux
public class Router {
    @Bean
    public RouterFunction<ServerResponse> router(AppController controller) {
        return RouterFunctions
                .route(GET("/product/state"), controller::handleGetProductStateRequest);
    }
}

Controller

@Component
public class AppController {
    private final ProductRepository repository;
    public AppController(ProductRepository repository){
        this.repository = repository;
    }
    /**
     * Get product state as stream
     * This handler function processes GET requests and sends a response
     */
    public Mono<ServerResponse> handleGetProductRequest(ServerRequest ignoredRequest) {
        Flux<Product> products= repository.getProductStream();
        return ServerResponse.ok().header("Access-Control-Allow-Origin", "*")
                .contentType(MediaType.TEXT_EVENT_STREAM)
                .body(products, Product.class);
    }
}

pom.xml

<dependencies>
    <dependency>
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-starter-webflux</artifactId>
    </dependency>
    <dependency>
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-starter-tomcat</artifactId>
       <scope>provided</scope>
    </dependency>
    <dependency>
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-starter-test</artifactId>
       <scope>test</scope>
    </dependency>
    <dependency>
       <groupId>io.projectreactor</groupId>
       <artifactId>reactor-test</artifactId>
       <scope>test</scope>
    </dependency>
</dependencies>