springboot Postgres : After certain time, service stops responding, required restart

Question

Created postgres sequence, and GRPC service hit this sequencer to generate a new sequence. When ever it required new sequence, grpc service is hit and it will provide a new sequence, now this sequence can be used as some serial/ID etc.Long story short, Donot need to save this sequence in any table or column, Hit service get the sequence. service is working fine, but the problrm is after every 45-60 min service need to restart. Tried lot of solution mention is Stackoverflow Postgres connection has been closed error in Spring Boot

but it didnot help,

Getting this error

HikariPool-1 - Connection is not available, request timed out after 30000ms.",org.hibernate.engine.jdbc.spi.SqlExceptionHelper.logExceptions(SqlExceptionHelper.java:142)

response_description: Could not open JPA EntityManager for transaction; nested exception is org.hibernate.exception.JDBCConnectionException: Unable to acquire JDBC Connection

Could someone please look suggest, what doing wrong here?

Thanks in Advance !!

@Repository
public class SequenceNumberRepository {

    @PersistenceContext
    private EntityManager entityManager;

    @Transactional
    public BigInteger getNextSequenceNumber(String sequencer) {
        BigInteger sequence = null;
          try {
              Query query = entityManager.createNativeQuery("SELECT nextval(:param)");
              query.setParameter("param", ConstantUtil.SEQUENCER_NUMBER + ConstantUtil.PERIOD_CONSTANT +sequencer);
              sequence = (BigInteger) query.getSingleResult();
          }catch(Exception e){
              e.printStackTrace();
          } finally {
              entityManager.close();
          }
        return sequence;
    }
}

application.yml

spring:
  config:
    activate:
      on-profile: dev
  datasource:
    url: "jdbc:postgresql://<server>:<port>/abc_dev?currentSchema=sequence_number"
    username: abc
    password: abc
    test-on-borrow: true
    validation-query: SELECT 1;
  jpa:
    properties:
      hibernate:
        dialect: org.hibernate.dialect.PostgreSQLDialect