What guidelines should Digitec/Galaxus follow?

Both standards are assigned by the manufacturer, the IP rating describes the resistance to dust and water. Samsung itself no longer gives a guarantee in the event of a defect (https://www.samsung.com/global...).
MIL-STD-810, also describes only a series of tests for the "survival capabilities" of a device. This standard is more of a joke than anything else...

So both of these certifications refer to the device itself and what it should survive, and make no statement about warranty handling/repair.... These are two completely different pairs of shoes...