I’m in the North West.
Problem started using a Fairphone USB cable and an iPhone plug, but i’ve tried various plugs and various cables including an ipad cable, a playstation 5 cable, basically any cable I could find that has USB C, various plugs, mostly apple but some unbranded, i’ve got dozens and they all do the same. At work I plugged the USB cable directly into a USB extension lead. So all types of cables from all different brands with different power sources. I don’t really know much about this stuff so I’m not 100% sure what you mean by USB A or USB 3, but for 18 months the phone worked perfectly with all of these, as I would regularly charge it both at work and at home using a variety of power sources, whichever was convenient.
I’m really sorry but I’ve tried reading that link and I have no idea what any of it means. I just want my phone to work 
if I can’t charge it using the official Fairphone charger plugged into the mains then surely the product is faulty? Do you have any advice on exactly which cables/plugs I should be using to charge it to prevent the problems described in the link?
Thanks again for replying and I’m sorry I don’t understand all of this!