unreachable pattern match warning for type test of enum where case mixes in sealed trait

[bishabosha]

Compiler version

3.5.2, 3.6.2-RC1

Minimized code

sealed trait Decorated

enum Foo:
  case A
  case B extends Foo with Decorated

def decoratedFoo(a: Foo): Option[Decorated] =
  Some(a).collect { case a: Decorated => a }

Output

1 warning found
-- [E030] Match case Unreachable Warning: --------------------------------------
1 |def decoratedFoo(a: Foo): Option[Decorated] = Some(a).collect { case a: Decorated => a }
  |                                                                     ^^^^^^^^^^^^
  |                                                          Unreachable case

Expectation

I would think that the space analysis can realize that children of one sealed class can intersect with children of an otherwise "unrelated" sealed trait

[sjrd]

Duplicate of #21860, fixed by #21876?

[bishabosha]

looks like it, well the nightly has fixed my original problem