Class 2 or Class 3 voluntary contributions to pay from abroad and when to stop?

I have lived and worked in Australia since 2011 and recently paid Class 2 contributions to fill missing years. I have since received a confirmation letter from HMRC confirming my record has been updated to end of FY22/23. At the same time I received requests to make additional Class 2 payments to April 2024 AND ALSO Class 3 payments for the same period. Presumably I only need to pay once? However, from 1987 - 2011 I was in full time PAYE employment in UK so NI contributions up to 2023 should give me 35 full years. Should I, and do I need to keep on making voluntary contributions to secure my state pension? (Since my missing contributions were accepted in June 2024, I have not been able to check my pension or NI records online. I just get a "problem with this service" message).

Hi Chris,
To check your entitlement to a UK State Pension may I ask that you apply for a State Pension Forecast via Check your State Pension forecast.
This will advise if you have a full pension entitlement.
If, once you have received your Forecast, you wish to stop paying voluntary contributions then please call our National Insurance Helpline
on 0300 200 3500 (from the UK) or +44 191 2037010 (from overseas) and they will be able to help you.
Thank you.