Sorry, Krzysztof. Nothing missing is the same code I have, but... now I remembered that I had left more this BS_MULTILINE style in the functions: INITRADIOGROUP, INITRADIOBUTTON and SETRADIOSTYLE of the HMG source code. It had done in test character and ended up staying.
But now even removing and in trying to set style with BS_MULTILINE does not work the same way as when the RadioGroup is started.

I have no idea how to solve it. All tests I just done, doesn't work as being native of HMG function with plus this BS_MULTILINE.
Here's the executable file to be tested at yours:
It may would be solved if Claudio would accept BS_MULTILINE as more one property in the RadioGroup Style.
Anyway with ITEM_HEIGHT as 28 or handled higher, MULTILINE remains a necessary property and without prejudice.
Could it be done this Claudio ?