Kotlin Serialization Properties.decodeFromMap returns null for nullable types

Kotlin Serialization Properties.decodeFromMap returns null for nullable types.
Nullable fields are populated if the value is present in the map.
For consistency, same behaviour should be expected at top-level nullable type.
Or else this behaviour should be documented to avoid confusion.

import kotlinx.serialization.ExperimentalSerializationApi
import kotlinx.serialization.Serializable
import kotlinx.serialization.properties.Properties
import kotlinx.serialization.properties.decodeFromMap

@Serializable
data class User(val id: String)

@ExperimentalSerializationApi
fun main() {
    val map = mapOf("id" to "some user id")

    val user: User = Properties.decodeFromMap(map)
    println("user: $user") // user: User(id=some user id)

    val nullableUser: User? = Properties.decodeFromMap(map)
    println("nullableUser: $nullableUser") // nullableUser: null
}