Oh, yes. I’ve once met such problem when cooperating with another programmer writing Java.
The “default method” in interface written in Kotlin is also been requested to rewrite the method body while implementing in Java (even the Kotlin is targeted to Java 8).
It seems that only when you write the method body in Java, that you can implement (or extend) the interface (abstract class) without rewriting. All the “default methods” written in Kotlin are invisble in Java.