Hello - did you get any joy with this Nsim?
I'm another casualty of the whole email address change saga, I haven't been able to access my Virgin.net web mail for months until I realised last night what the issue was (always would get the "Forbidden" error) - so having sifted through many forums I finally stumbled across the 3rd party email requirement, which all actually makes complete sense once your know the 2FA reasoning behind it....
Anyway I digress, thinking I was onto a winner & whilst in my account settings updated my password to a more secure one (as prior to this VM password criteria was somewhat restrictive) went to log into my .net webmail to add some long need folders & was hit with a Biometrics "no security key present on device" message.
There is an option to login with the password instead, you know the one I just changed (which i wish to kingdom come I hadn't now & at least tried the old one prior, to ensure accessibility) but that was declined with a message saying that either the email address / password was wrong - which they aren't as Google saved both for me as I was going them & I of course got the confirm email address auto generated email from VM additionally too anyways, so it's deffo not that with which the issue lies.....
Anyhoo - back to the main issue at hand, the only alternate viable option left is to request a password re-set via the link but then after entering the newly updated email address I get the same message as yourself: "Oops... Something went wrong. Please try again later".
I'm a relatively tech savvy person, but this whole run around change of email address process / lack of clarity & subsequent ability to log-in is just completely perplexing & bonkers!! 😖
