Spring Boot Upgrade Redis – Null key returned for cache operation

After the spring 3.x upgrade Redis Cache gives

Null key returned for cache operation

spring-boot version: 3.2.2

<dependency>
  <groupId>redis.clients</groupId>
  <artifactId>jedis</artifactId>
  <version>5.1.0</version>
</dependency>
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-data-redis</artifactId>
  <exclusions>
    <exclusion>
      <groupId>io.lettuce</groupId>
        <artifactId>lettuce-core</artifactId>
    </exclusion>
  </exclusions>
</dependency>

Cachable Method:

@Cacheable(value = "user", key = "#username", unless = "#result == null")
public String findUsername(String username) {
    ...
}

but if I use key = "#a0" instead of key = "#username", the problem is solved.

@Cacheable(value = "user", key = "#a0", unless = "#result == null")
public String findUsername(String username) {
    ...
}

There was no need to do it this way in the previous version.
My previous versions:

spring-boot version: 2.7.4
redis.clients jedis version :3.9.0

What is the reason?