Friend reported same problem. The Submit produces following errors:
Tested in Chrome, Edge and IE11
POST https://account.arena.net/register?alt=gw2 400 (Bad Request)
register?alt=gw2:1
Refused to execute script from ‘https://account.staticwars.com/gen/rollup.15332777.js’ because its MIME type (‘text/html’) is not executable, and strict MIME type checking is enabled.