You could try a little bit of sand until tomorrow. The one with the full crop needs to have food with held over night so you can tell if it goes down at all. If it's smaller in the morning that is a good sign. The first week of life, it's better to raise chicks on something other than shavings...
Hi, Welcome to the flock! did you raise them on shavings from day one? It is possible that the chick ate shavings and is clogged up. I don't know what to do about that except to provide baby grit. Maybe someone else know something else that would cause the problem and how to fix it.