TypeTest matching does not seem to work from singleton types

[LPTK]

Minimized code

import scala.reflect.TypeTest

extension [A](self: Any) def being(using TypeTest[self.type, A]) =
  self match { case self: A => Some(self); case _ => None }

Output

def being[A](self: Any)(using reflect.TypeTest[self.type, A]): Option[A]
2 |  self match { case self: A => Some(self); case _ => None }
  |                    ^^^^^^^
  |                    the type test for A cannot be checked at runtime

Expectation

Should compile. The following manual version works:

import scala.reflect.TypeTest

extension [A](self: Any) def being(using test: TypeTest[self.type, A]) =
  test.unapply(self)