Confusing behaviour of abstract contracts

[Antigen-1]

What version of Racket are you using?

> (version)
"8.13.0.3"

What program did you run?

> (module test racket/base
    (require racket/contract)
    (provide (contract-out #:forall (a?)
                           (struct test ((a a?)))))
      
    (struct test (a)))
> (require 'test)
> (test 1)
test: broke its own contract
  not a?: 1
  in: the 1st argument of
      (-> a? test?)
  contract from: top-level
  blaming: top-level
   (assuming the contract is correct)
  at: string:7:10
 [,bt for context]

What should have happened?
The first a? in the contract shown in the error message is in the negative position so that the value 1 should have been accepted anyway and wrapped in an opaque struct.

If you got an error message, please include it here.
The context may be helpful.

> ,bt
test: broke its own contract
  not a?: 1
  in: the 1st argument of
      (-> a? test?)
  contract from: top-level
  blaming: top-level
   (assuming the contract is correct)
  at: string:7:10
  context...:
   /usr/racket/share/racket/collects/racket/contract/private/blame.rkt:350:0: raise-blame-error
   /usr/racket/share/racket/collects/racket/contract/private/arrow-val-first.rkt:486:18
   /usr/racket/share/racket/pkgs/xrepl-lib/xrepl/xrepl.rkt:1573:0
   /usr/racket/share/racket/collects/racket/repl.rkt:11:26

Please include any other relevant details
(test 1 add1) returns an instance of the test structure type in Racket8.12.

Besides, a procedure that is not a structure constructor and is protected by a similar contract works fine.

> (module test racket/base
    (require racket/contract)
    (provide (contract-out #:forall (a?)
                           (test (-> a? any))))
      
    (define (test a) a))
> ,r 'test
> (test 1)
#<a?/∀>

[Antigen-1]

This error can't be reproduced with Racket 8.13. I will close this issue.