Backup your current configuration, flash the OEM firmware, submit the feedback, re-flash Merlin, reload your configuration.
I did this for another problem, no reaction anymore after the first issue has been done with merlin FW on it ...
That is what happens when you buy an international/grey import (trying to get a cheaper price?) router.
You get the original language and have to change it to suit your needs.
What happens when a Chinese version router is used in Russia , Japan, India?
Do you think the GUI is going to magically alter the language for those countries.
Buy from a dealer in your locale and you get a router in your language.
It is not difficult to add your login and password then change language .
I had an international version AVM Fritz!Box , guess what , the damn GUI was in German till I changed it .
ASUS as you know don't use this site, Merlin can't help you as it is nothing to with his firmware .........
This is INTERNATIONAL version of the router NOT chinese exclusive or like yours US or EU versions with fixed region setting, I am allowed and able to change the region to my needs/location !
And NO its not a grey import, and I did not try get a cheaper price I got it for about half price!!!
I can set region in config according to my region (EU, US, Australia, Korea, Asia, China).
But not the language on special startup-pages where it should be done!
You can easily translate german to english and most other languages incl. chinese with google, not a really problem, even if you have to type it by hand!
But you cant do so with chinese if you have fields you can not copy and paste, I cant draw this symbols or load as bmp for translation and dont know the codes for this "letters".
Change language is easy after login to the router, but after factory reset they dont appear, there are special startup pages you have to select some things, NO user/pw at this point !!!