Thanks, it's quite odd. My wife's account I can register, but mine gives an error that "something went wrong and the request could not be submitted" even though account is in good standing, I can log into account via app and website and even turned off my usual VPN etc. Password is correct, I viewed it and I passed the captcha as well.

Probably I'll wait for the promo email from Hilton and try again then. Never happened before, still signed up for current promo that runs till 1 May, but also have a stay mid-May so want to register for that (still a bit of time of course).