I used it before, everything was fine, but it seems that in running my application as a Java Project and not a Spring Boot Application from STS, it did not force a restart of the server.
I found this:
https://stackoverflow.com/questions/49386434/live-reload-not-working-in-spring-boot-devtools
“Developer tools are automatically disabled when running a fully packaged application.
If your application is launched from java -jar, you don’t use the spring-boot maven plugin to run your application.”