I'd be SORELY tempted to call Weber Customer Service while I'm standing at the counter at that Ace, and drag the manager into a speakerphone conversation. Somebody ain't tellin' me what's right, so suppose YOU two figure it out.
I wouldn't necessarily expect the greatest sear in the world, but you should be able to get something. You get a good sear from a direct heat source exposure, and that heat source does have to be lit up pretty well. On a gasser..... there's the usual fuel suspects like an OPD malfunction (try another tank,) air/fuel mixture (adjust the air shutters,) maybe the fuel regulator. Yeah, I know, there's a distance aspect for sure.