Error with Unsupported Match Pattern in TypeScript

const matcher = Match.type<{ start: AB | null; end: AB | null }>().pipe(
  Match.when({ start: null, end: null }, () => Effect.fail("")),
  Match.when(
    { start: Match.instanceOf(A), end: Match.instanceOf(A) }, // error here
    ({ start, end }) => Effect.succeed(['as',start, end] as const)
  ),
  Match.when(
    { start: Match.instanceOf(B), end: Match.instanceOf(B) }, // error here
    ({ start, end }) => Effect.succeed(['bs', start, end] as const)
  ),
  Match.orElse(() => Effect.fail("Unsupported case"))
)

src/main.ts(13,7): error TS2353: Object literal may only specify known properties, and 'start' does not exist in type 'PatternPrimitive<never>'.