The disappearance of Murray threw this whole offense out of whack. It was obvious he was going to be a big player in this offense, esecially to counter the Commanders love of blitzing against the Cowboys. The offense, on the first series, marched up the field and scored easily. After that, the offense just stalled.
Problem is, it doesn't look like Dallas adapts well during a game. The spread happened late and that is what gave the offense life, outside of Special teams. It is like Dallas just has a tendency to go max-protect as others have pointed out and stall. They should actually become more aggressive apparently and way more fearless.