Input symbols are different from the key code name on non-ANSI keyboards
This is the intended behavior.
The key code name using in Karabiner-Elements is HID usage name. This is close to the physical key location on the ANSI layout keyboard.
For this reason, there are mismatches of symbols actually input and key code names on non-ANSI keyboards.
Determining which characters are to be input by keyboard event is the later step in the processing flow of macOS. Karabiner-Elements changes input events on a layer closer to the hardware, which is why it works like this.
Please use key code names that matches your layout.
Key code table
|Key code name