From the article Here:
Nineteen missiles fired outside Syrian airspace by two B-1B bombers targeted the Barzah Research and Development Center located in the greater Damascus area. Those Joint Air to Surface Standoff Missiles, or JASSMs,
Tracking a pre-planned route from launch to target using Global Positioning Satellites and an internal navigation system, the missile is designed to strike with a 1,000-pound penetrating warhead.
I guess that the Russian GPS jamming capability didn’t work that well or some of those missiles were set for home on jam capability.