He's been bad for a few weeks now. Not sure if it's him being tired (doesn't sound like he rested any during the break), or is nursing an injury, or if he's upset over the Jones situation (which Pat Boyle confirmed did rub some players here the wrong way). Whatever it is, it'd obviously be nice if he can snap out of it.
His skating isn't great, but it's fine. He's generally been the best, or among the best, here in the transition game. He's not a speedster like Jack Hughes is. He's a guy that often pulls up at the blue line and waits to hit a rushing teammate with a pass, similar to what Kane was known to do a lot here.
His speed won't hold him back from being an elite player. It didn't for Kane, or Kucherov, or Kaprizov. All of them are wingers and maybe that's where he winds up long term. I've personally been an advocate for him at center and felt that he's done well there at points this season.
Don't think him playing center or his overall skating is what's causing these issues the past few weeks, though. It hasn't been an issue before. Just gotta be patient with him and remember that he's a 19yo kid. I think most, though certainly not all, of us here know and have seen what he's capable of, so we can give him the benefit of the doubt a little bit. He'll be fine, even though he's not fine right now.