Consider the following code fragment:

public abstract class GenericsAutocompletion<T extends Collection> {
    
    abstract void abstractMethod();
    
    public static void method(GenericsAutocompletion<? super List> arg) {
    }
    
    public static void main(String[] args) {
        method(new |);
    }
}

Invoke code completion (Ctrl-Space) after new operator at '|' symbol and press Enter, the line becomes like this:

        method(new GenericsAutocompletion<List>);

The problem is the selection in the list is incorrect. It is AbstractMethodError, not the list of super to List. And code completion doesn't go further to abstractMethod implementation.

This code is quite common in JavaFX with EventHandlers so this is highly visible NetBeans issue.