Calligraphy Pen Problems

Is anyone using wide calligraphy pens in this community? I tried my first with a 6mm wide nib and found it really hard to get a smooth line. As well as not constantly touching the paper with its whole width, and drawing only partial lines, in certain directions it would actually scratch the paper and I can see more of that would damage the nib eventually too.

I have seen YouTubers mounting such pens and achieving nice smooth lines, and they mounted the pens perfectly vertically, rather than diagonally, which I’ve tried to do also. I have messaged them also but no response so far so asking here too for any tips. Thanks.