Suse versions keep on setting language variables to non-existent locales.
It affects LANG and LC_CTYPE at least.

LC_CTYPE          = 'en_US.UTF-8'

This is wrong.

locale -a|grep en_.\*utf -i
en_AU.utf8
en_BE.utf8
en_BW.utf8
en_CA.utf8
en_DK.utf8
en_GB.utf8
en_HK.utf8
en_IE.utf8
en_NZ.utf8
en_PH.utf8
en_SG.utf8
en_US.utf8
en_ZA.utf8
en_ZW.utf8

No such value exists. E.g. libreoffice can complain/fail on this, plus it
doesn't do a lot either.

Problem has existed since at least 12.1, and exists in factory.
Its origin may be in
/etc/sysconfig/language
RC_LANG="en_US.UTF-8"

Perhaps yast has a table of wrong values to put in there during initial
installation.