Redis – Spring Boot: error when activating profile in YAML file

I can’t activate a profile dynamically in a Spring Boot app. I defined profiles in pom.xml as follows:

<profiles>
        <profile>
            <id>dev</id>
            <properties>
                <activatedProperties>dev</activatedProperties>
            </properties>
            <activation>
                <activeByDefault>true</activeByDefault>
            </activation>
        </profile>
        <profile>
            <id>prod</id>
            <properties>
                <activatedProperties>prod</activatedProperties>
            </properties>
        </profile>
    </profiles>

Then I created 2 files in src/main/resources:

# application.yml

spring:
  application:
    name: myapp-service
  profiles:
    active: @activatedProperties@
server:
  port: 8200

Here is application-dev.yml:

spring:
  kafka:
    producer:
      bootstrap-servers: localhost:9092
      key-serializer: org.apache.kafka.common.serialization.StringSerializer
      value-serializer: org.apache.kafka.common.serialization.StringSerializer
redis:
  host: localhost
  port: 6379

When starting the app from the IDE, it fails to read active: @activatedProperties@ values rating the error about @ symbol:

java.lang.IllegalStateException: Failed to load property source from target/classes/application.yml'
...
Caused by: org.yaml.snakeyaml.scanner.ScannerException: while scanning for the next token
found character '@' that cannot start any token. (Do not use @ for indentation)
 in 'reader', line 5, column 13:
        active: @activatedProperties@
                ^

I found some examples of the same use but in application.properties file.
Isn’it possible to do the same in a yml file ?

I tried to replace it with $ sign as follows:

...
  profiles:
    active: ${activatedProperties}

This time it is Spring Boot that raised the error about failing to load redis.host value:

Factory method 'redisConnectionFactory' threw exception; nested exception is java.lang.IllegalArgumentException: Host name must not be null or empty!

as if the profile is not recognized.

Here is the configuration file:

@Configuration
@EnableConfigurationProperties
@ConfigurationProperties
public class AppConfiguration {
    private String redisHost;
    private int redisPort;
    private String redisPassword;
... //getters and getters come here

Here is the Spring Boot application class:

@SpringBootApplication
public class LiveDataServiceApplication {

    @Autowired
    private AppConfiguration configuration;

    public static void main(String[] args) {
        SpringApplication.run(LiveDataServiceApplication.class, args);
    }

    @Bean
    public RedisConnectionFactory redisConnectionFactory() {
        RedisStandaloneConfiguration redisConfiguration = new RedisStandaloneConfiguration(configuration.getRedisHost(), configuration.getRedisPort());
        redisConfiguration.setPassword(configuration.getRedisPassword());
        return new LettuceConnectionFactory(redisConfiguration);
    }

What am I missing?

UPDATE

I annotated every attribute in AppConfiguration class with `@Value():

public class AppConfiguration {

    @Value("${redis.host}")
    private String redisHost;

    @Value("${redis.port}")
    private int redisPort;

    @Value("${redis.password:}")
    private String redisPassword;
...

and moved the values to application.ymland it worked!
If I keep the vaues in application-dev.yml file, it fails to load them.
Why so? It seems like the default profile dev is not set.

UPDATE-2

Finally, it worked if I use a single YAML file application.yml including available environments as follows:

spring:
  application:
    name: live-data-service
  profiles:
    active: ${activatedProperties}
  kafka:
    producer:
      bootstrap-servers: localhost:9092
      key-serializer: org.apache.kafka.common.serialization.StringSerializer
      value-serializer: org.apache.kafka.common.serialization.StringSerializer
server:
  port: 8200
redis:
  host: localhost
  port: 6379
---
spring:
  profiles: prod
  kafka:
    producer:
      bootstrap-servers: prod-kafka.server:9092
      key-serializer: org.apache.kafka.common.serialization.StringSerializer
      value-serializer: org.apache.kafka.common.serialization.StringSerializer
redis:
  host: prod.server.com
  port: 6379
  password: prod-server-pwd

at least locally? I have no idea why id does not when using separate YAML files (application-dev.yml, application-prod.yml, etc.
Offcial Spring Boot docs have no more details about that.