Same here when I just tried yesterday. Was on the Razer Store page, could not checkout--failed to load the shipping page:
Webpage shows a loading progress circle. Opening Developer Tools shows page errors.
I reloaded the website in Microsoft Edge, which I confirmed works (but by then the product I was trying to purchase unfortunately sold out).
I verified Adblocker is not turned on. Also I was checking this Reddit page at the same time which also does not load: