Problem with Method reference operator and CompileStatic

Question

In the following code, @CompileStatic does not work in combination with the method reference operator for Groovy methods collect and find, although it works with Java streams or the method pointer operator. Am I doing something wrong or is this not supported?

The code does not compile using Java 17 and Groovy 4.0.15.

import groovy.transform.CompileStatic

@CompileStatic
private void groovyFuncWithMethodPointer(int n) {
    // works
    def res = (1..n).collect(this.&calc)
            .find(this.&isEven)
}

@CompileStatic
private void groovyFuncWithMethodReference(int n) {
    // does not work
    // org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
    // ideaGroovyConsole.groovy: 15: The argument is a method reference, but the parameter type is not a functional interface
    def res = (1..n).collect(this::calc)
            .find(this::isEven)
}

@CompileStatic
private void streamFuncWithMethodReference(int n) {
    // works
    def res = (1..n).stream()
            .map(this::calc)
            .filter(this::isEven)
            .findFirst()
}

int calc(int x){
    return 2*x+1
}

boolean isEven(int x){
    return x % 2 == 0
}