His stuff is about the same from his last two MiLB starts.
But if you follow through all of Nestico's posts, what I can gather is that Manoah has pretty average stuff and it has remained somewhat consistent, even during his struggles. The location and walks are what is killing him.
It's hard to see how he was ever as good as he was with the stuff he had. But with good command, a solid fastball, a 4 pitch mix, and good extension he can be really good. Just needs that command to return.