I have tried 4 different USB-C chargers with my Dell XPS 13 but none of them charges it.

I want to lug around only one charger and that should charge all of my devices, so I want to switch to an USB-C charger and leave the original at a fixed place.

All tested chargers ar PD compatible, ranging from 45 to 80W. Most of them have normal USB-A charging ports in addition to the PD / USB-C port and all of them charge phones with high power (tested them they supply 2-3 A at 5V, so the chargers themselves work well with normal USB charging).

One of them was an Apple Macbook Pro charger which is supposed to work with these machines.

The 80W charger advertises itself as PD 2 compatible and specifically mentions Dell USB-C laptops as compatible.

I have BIOS 2.5.1 on the machine (2018-FEB).

I am using it with Ubuntu 16.04 (I could only order a Windows based one but removed Windows completely).

How can I debug the charging problem? How can I tell why the machine refuses to charge?

The BIOS settings doesn't have diagnostics for this.