"ls" sorting directories/files differently if the start with "d" or "p"?

ls-sorting.txt

$ mkdir config config-example
$ touch config/d config-example/d
$ touch config/p config-example/p
$ ls config*/d
config/d  config-example/d
$ ls config*/p
config-example/p  config/p
$ # Why is the sort order different??
$ locale
LANG=de_AT.UTF-8
LANGUAGE=de_AT:de
LC_CTYPE="de_AT.UTF-8"
LC_NUMERIC="de_AT.UTF-8"
LC_TIME="de_AT.UTF-8"
LC_COLLATE="de_AT.UTF-8"
LC_MONETARY="de_AT.UTF-8"
LC_MESSAGES="de_AT.UTF-8"
LC_PAPER="de_AT.UTF-8"
LC_NAME="de_AT.UTF-8"
LC_ADDRESS="de_AT.UTF-8"
LC_TELEPHONE="de_AT.UTF-8"
LC_MEASUREMENT="de_AT.UTF-8"
LC_IDENTIFICATION="de_AT.UTF-8"
LC_ALL=