Current Draw with Stepped Down Voltage
It depends on what you use to step down the voltage. If you use a switching regulator, you are mostly correct, less inefficiencies in the regulator.

On the other hand, if you use a linear regulator, you’ll see a 1 amp (plus inefficiencies) draw on the 24 volts.

In either case, the losses will show up mostly as heat. With the linear, the regulator will put out 19 watts of heat.