This is not good. I don’t see how they can claim their goals were reached if the Houthi are still advancing. This is a quit and go home approach. Perhaps with the U.S. Naval ships in the area they are looking at starving the rebels of arms and re-supplies.
IMO, it seems that the combination of the Saudi’s unable to trust there own green ground troops to fight, plus being unable to buy/bribe another nation to the fighting for them, plus the very real possibility of a big confrontation with Iran in just the next few hours prompted this.