STC instantiates type variable with a wrong type when calling an instance method of the same class

import java.util.function.Function;

class A<T> {
  T y;
  void foo(T x, Function<T, T> func) {
    foo((true) ? x : y, func)
  }
}

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
test.groovy: 6: [Static type checking] - Cannot call A#foo(java.lang.Object, java.util.function.Function<java.lang.Object, java.lang.Object>) with arguments [java.lang.Object<T>, java.util.function.Function<T, T>]
 @ line 6, column 5.
       foo((true) ? x : y, func)
       ^

1 error