with-syntax return error in Guile, not in Kawa or Racket

hi,

Guile:

(base) mattei@mbp-touch-bar Scheme-PLUS-for-Guile % guile
GNU Guile 3.0.8.99-f3ea8
Copyright (C) 1995-2022 Free Software Foundation, Inc.

Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
This program is free software, and you are welcome to redistribute it
under certain conditions; type `,show c' for details.

Enter `,help' for help.
scheme@(guile-user)> (define-syntax test-it

   (lambda (stx)

    (syntax-case stx ()

    ((_ term1)

     (with-syntax ((var (syntax->datum #'term1)))

       #'var)))))
scheme@(guile-user)> (test-it (+ 2 3))
While compiling expression:
Syntax error:
unknown file:#f:#f: encountered raw symbol in macro output in subform + of
(test-it (+ 2 3))

Kawa:

(base) mattei@mbp-touch-bar Scheme-PLUS-for-Guile % kawa
#|kawa:1|# (define-syntax test-it
#|.....2|#
#|.....3|#    (lambda (stx)
#|.....4|#
#|.....5|#     (syntax-case stx ()
#|.....6|#
#|.....7|#     ((_ term1)
#|.....8|#
#|.....9|#      (with-syntax ((var (syntax->datum #'term1)))
#|....10|#
#|....11|#        #'var)))))
#|....12|#
#|kawa:13|# (test-it (+ 2 3))
5

Racket:

Language: racket, with debugging; memory limit: 8192 MB.
> (define-syntax test-it

   (lambda (stx)

    (syntax-case stx ()

    ((_ term1)

     (with-syntax ((var (syntax->datum #'term1)))

       #'var)))))

> (test-it (+ 2 3))
5

why,why?

Damien