pretty-print and pp does not print UTF-8 characters

[Kirill Lisovskiy]

csi 6 (installed from ​https://code.call-cc.org/dev-snapshots/2025/10/25/chicken-6.0.0pre2.tar.gz):
Version 6.0.0pre2 (rev e4e9ea4d)
linux-unix-gnu-x86-64 [ 64bit dload ptables ]
(import (chicken pretty-print))
(pp "été")
=> "\xe9;t\xe9;"

(pretty-print "été") has the same problem in Chicken 6,

Unicode code point for é is U+00E9
(display "\xe9;") => é
(display "é" => é
both work. print and write also work fine.
Could it be that interpretations of backslashes is disabled ?

csi 5:
Version 5.2.0 (rev 317468e4)
(import (chicken pretty-print))
(pp "été")
=> "été"