Poor man's solution - I was having the same issue, where IF I could get a macro to get it to sleep, it was popping back on again. I tried running a macro to manually hit a hot corner, but the only one that seemed to work was the upper left, which I kept activating by accident with my cursor. So:
I just recorded the screen actions of going to the Apple menu then down arrow & select Sleep - it ain't pretty but it works perfectly!