Hi,
a little update: this happens because /usr/NX/scripts/setup/nxserver checks /etc/lsb-release which is a bad idea because all the DISTRIB_ fields are optional! On my systems /etc/lsb-release shows only the LSB_VERSION line.
You should either continue with /etc/os-release etc. if no OS could be detected with /etc/lsb-release or rely only on os-release for SuSE systems as this file is mandatory for SuSE.
cu,
Frank
P.S.: It seems to be impossible to reset the password. After getting the reset link and entering a new password, the login with exactly this password doesn’t work either… So I had to create a second login to write this answer 🙁