Hi there,
I deleted your second post. You don’t need to reply to yourself. You can include everything you need to in your first post. I moved all of the information you included in your second post into your first post.
Regarding your bug report, I do not think that this is a bug. When you start an aircraft on the runway, the simulation starts in a situation where you are ready to takeoff. At that point in time, there are no ATC commands available to you. It is the same in English. Note that in this video with English enabled, I cannot say anything to ATC. It’s the same as in Korean:
However, if you start the aircraft cold and dark, you will be able to communicate. Look at this video where I started an aircraft with Korean turned on, and then I communicated with ATC:
In your original scenario, if you want to communicate with ATC when starting on the runway, first takeoff. Then, ATC options will become available to you.