Stranded Bear is obviously the expert on this, so I bow to her opinion, and if she says she had a hard time because of it, then I would say don't do it, but if I saw the name Stevie, I would assume it was a girl, and if I met a boy or man called Stevie, I would think "that's a bit of a girly name for a boy".
Can I add the poet Stevie Smith to the mix?
I just googled stevie and of course it came up with Stevie Wonder - a man - but I've never thought of him being called Stevie because I just think of his name altogether "Stevie Wonder". I bet when people address him directly, they call him Steve.
Now I've typed it so many times, it has begun to look very odd.