Whenever I have had such position changes, I have not modified my visa (which had a good enough generic title of including the word "manager" in any case).
However, every time I did get an official letter from my company, and signed a revised "official" labour contract with my revised salary details (this is the labour contract which is filed in the system with MOL).
However, every time I did get an official letter from my company, and signed a revised "official" labour contract with my revised salary details (this is the labour contract which is filed in the system with MOL).