Changing language on a Bluetooth keyboard

I have Logitech K780 keyboard that connect perfect with my iPhone but i have a really big troubles when i try to type with Cyrillic letters.

When i switch language by pressing ctrl + space. Bulgarian letters change their places when i typing trought Logitech keyboard.

I tasted with all Bulgarians keyboards into from my iPhone settings (keyboard)

I hope it is a bug that could be fixed

Thank you