Repository that reproducing the error - https://github.com/ssserj/spring-demo I did not check the app on previous versions spring boot, but here is a typical example of using Prototype Bean:

@Service
@Scope("prototype")
@Slf4j
public class PrototypeBean implements BeanFactoryAware {
    @Getter
    private final String name;
    protected SingletonBean singletonBean;
    protected BeanFactory beanFactory;

    public PrototypeBean(String name) {
        this.name = name;
    }

    @Override
    public void setBeanFactory(BeanFactory beanFactory) {
        log.info("PrototypeBean is called with name " + name);
        this.beanFactory = beanFactory;
    }

    @Autowired
    public void setSingletonBean(SingletonBean singletonBean) {
        this.singletonBean = singletonBean;
    }

    public void process() {
        System.out.println("PrototypeBean is called with name " + name);
        System.out.println("PrototypeBean is called by beanFactory at " + this.beanFactory.getBean(SingletonBean.class).getTime());
        System.out.println("PrototypeBean is called by singletonBean at " + singletonBean.getTime());
    }
}

Spring 3.5.8 Java - 21.0.9 OS - MacOS, Linux

Basic Spring App

mvn clean package
java -jar target/demo-0.0.1-SNAPSHOT.jar

Expected result:

 :: Spring Boot ::                (v3.5.8)

2025-11-22T15:35:34.140+03:00  INFO 41206 --- [demo] [           main] com.example.demo.DemoApplication         : Starting DemoApplication using Java 21.0.9 with PID 41206 (/Users/s.sergeev/Code/demo-spring/target/classes started by s.sergeev in /Users/s.sergeev/Code/demo-spring)
2025-11-22T15:35:34.141+03:00  INFO 41206 --- [demo] [           main] com.example.demo.DemoApplication         : No active profile set, falling back to 1 default profile: "default"
2025-11-22T15:35:34.272+03:00  INFO 41206 --- [demo] [           main] com.example.demo.DemoApplication         : Started DemoApplication in 0.243 seconds (process running for 0.402)
2025-11-22T15:35:34.274+03:00  INFO 41206 --- [demo] [           main] com.example.demo.service.PrototypeBean   : PrototypeBean is called with name name1
PrototypeBean is called with name name1
PrototypeBean is called by beanFactory at 2025-11-22T15:35:34.274535
PrototypeBean is called by singletonBean at 2025-11-22T15:35:34.274572
2025-11-22T15:35:34.274+03:00  INFO 41206 --- [demo] [           main] com.example.demo.service.PrototypeBean   : PrototypeBean is called with name name2
PrototypeBean is called with name name2
PrototypeBean is called by beanFactory at 2025-11-22T15:35:34.274732
PrototypeBean is called by singletonBean at 2025-11-22T15:35:34.274750
2025-11-22T15:35:34.274+03:00  INFO 41206 --- [demo] [           main] com.example.demo.service.PrototypeBean   : PrototypeBean is called with name name3
PrototypeBean is called with name name3
PrototypeBean is called by beanFactory at 2025-11-22T15:35:34.274879
PrototypeBean is called by singletonBean at 2025-11-22T15:35:34.274891

AOT-processed Spring App

mvn clean package && mvn spring-boot:process-aot
java -Dspring.aot.enabled=true -jar target/demo-0.0.1-SNAPSHOT.jar

Produce error:

 :: Spring Boot ::                (v3.5.8)

2025-11-22T15:36:32.254+03:00  INFO 41605 --- [demo] [           main] com.example.demo.DemoApplication         : Starting AOT-processed DemoApplication using Java 21.0.9 with PID 41605 (/Users/s.sergeev/Code/demo-spring/target/classes started by s.sergeev in /Users/s.sergeev/Code/demo-spring)
2025-11-22T15:36:32.254+03:00  INFO 41605 --- [demo] [           main] com.example.demo.DemoApplication         : No active profile set, falling back to 1 default profile: "default"
2025-11-22T15:36:32.307+03:00  INFO 41605 --- [demo] [           main] com.example.demo.DemoApplication         : Started DemoApplication in 0.168 seconds (process running for 0.326)
2025-11-22T15:36:32.308+03:00  INFO 41605 --- [demo] [           main] com.example.demo.service.PrototypeBean   : PrototypeBean is called with name name1
PrototypeBean is called with name name1
PrototypeBean is called by beanFactory at 2025-11-22T15:36:32.309653
Exception in thread "main" java.lang.NullPointerException: Cannot invoke "com.example.demo.service.SingletonBean.getTime()" because "this.singletonBean" is null
    at com.example.demo.service.PrototypeBean.process(PrototypeBean.java:58)
    at com.example.demo.service.ProcessorBean.process(ProcessorBean.java:35)
    at com.example.demo.DemoApplication.main(DemoApplication.java:15)

BeanFactory works correctly. Explicit declaration and invocation of singletonBean from prototypeBean does not work in AOT processed application.