The Classic (2020) installer is supposed to include all languages. Where are you looking for the languages? Also, have you compared with installing from the EXE without extracting, to see if that does anything different?
first and foremost ... executing the SETUP.EXE in the ZIP file results in a question to extract all or to execute only
logic ... since it's a ZIP file
I used the extracted content to modify the setup.ini so it would ONLY install language 1043 (dutch) but this still doesn't do the trick.
using my deployment software actually installs dutch, but the program gets stuck in a loop after registering my license and afterwards signing in ... it never ends the loop of asking license and asking to sign in