IntelliJ IDEA Debug fails to start debugging

Unable to open debugger port (127.0.0.1:49897): java.net.SocketException "Socket closed"

I don't understand the specific reason, my solution steps:

1、tomcat shutdown.bat

2、tomcat startup.bat

3、IntelliJ IDEA  restart

4. Modify the JMX Port in the configuration

5. Modify Debug Prot

6、mvn clean

It's normal when I debug it again. I don't know what works. Let's play it one by one.