Windows uses the region chosen by the customer during device setup to identify if the PC is in the EEA. Once chosen in device setup, the region used for DMA compliance can only be changed by resetting the PC.
Uuh. I hope I have that set to my actual location despite using en-US as display language.
Thinking about it, I'm pretty sure it should be correct.
I hate when apps use your format settings instead of display language to decide the language they display. Having to reset the Windows installation would be a much bigger hassle though.