I understand your preference to use VSCode however regarding Java I would highly recommend you to use one of the Java IDEs. The Java Debugger/Plugins for VSCode (both from Microsoft and Red hat) are preview versions and it is very possible that there are issues espacially on a complex project with spring and maven involved and it is quite likly that there is nothing wrong with your code.
I use IntelliJ for the Java stuff but unfortunately spring not available in the community edition so whether you have a ultimate license from your university or the 30 day trail is enough or you have to use one of the other to IDEs.