Report and pay Capital Gains Tax on UK property HELP NEEDED PLEASE

Hi, I'm trying to report the capital gains tax on for my flat. I'm a uk resident, not a business etc. It should be straight forward. I have a gov gateway account from self assessment but from what I have read you also need a separate account to register capital gains from property. To set up the new account I go to - Report and pay Capital Gains Tax on UK property, selected new account sign up as an individual. I got a new gov gateway number, new password etc after entering all personal details. Then I get this :-- You need to sign in with different HMRC online details You’ll need to sign in with the same username and password you used to create your Capital Gains Tax on UK property account. a green button - SIGN IN WITH CORRECT DETAILS. I click this and it takes me to the same page with the same - sign in with correct details. I'm really stuck in a loop here? I am using the new gov gateway number and new password that I just set up the account with? I can see that lots of people also are stuck with this problem. Please help. Thanks.

Hi gjuptuituitui,
You will need to contact online services for this:
Technical support with HMRC online services 
Thank you.