springboot集成rabbit后，发送端没有重复发送，但消费端会重复收到消息，deliveryTag会+1，这是什么原因？

Question

spring.rabbitmq.virtual-host=/
spring.rabbitmq.addresses=xxx
spring.rabbitmq.username=xxx
spring.rabbitmq.password=xxx

spring.rabbitmq.publisher-confirms=true

spring.rabbitmq.publisher-returns=true
spring.rabbitmq.template.mandatory=true

spring.rabbitmq.listener.direct.acknowledge-mode=manual
spring.rabbitmq.listener.simple.acknowledge-mode=manual