Hi are these laptops?
If so, they can be configured to “sleep” or “hibbernate” after this period of time (even it being so short)
Do you have any BIOS Power Management configuration that shuts down some devices to save power?
Did you check if in the Adapter Properties\Power Management -> <i>Allow the computer to turn off this device to save power</i> checkbox ticked?
Please check all of this itms and post back your results.