Submitted CF83 in February; received HM Revenue letter to pay C3 for 23/24, but no catchup?

I have lived in the US for over 25 years, fully employed for that time and for more than 10 years prior to the leaving the UK. I submitted a CF83 in February 2024 with the checkboxes for paying both Class 2 and Class 3, and checked 'Yes' to know about the short fall I may pay. I had earlier (a year ago) submitted a CF83 that was identical except that I had checked Class 3 (and not Class 2), and was approved for Class 3 catchup payments. However, I was advised to apply for Class 2 as I appeared to meet the requirements to pay those instead. Today I received a letter from HM Revenue with a pay in slip to pay Class3 for calendar year 2023/24. Clearly the assumption is I'm paying Class 3 moving forward. However, I have NOT received any letter confirming whether I am approved to pay for my shortfall years. When I 'check progress' online it now indicates everything is complete (which surprises me - I wasn't expecting a response for several more months). I am concerned that my CF83 has been interpreted, and I'm not receiving the notice for approval (or not) of Class 2 back payments. Does anyone have experience of receiving a Class 3 payment notice for current/future payments before getting any indication of whether shortfall Class payments are approved? Thanks,

Hi,
It appears that your second application submitted in February 2024 hasn’t been processed yet.
The letter you have received for the 2023-2024 tax year will be your annual payment notification which had already been set up from your previous application.  
If your application was submitted online, these applications are currently being processed within 1 week.
You may wish to contact the National Insurance Helpline to check the progress of your application.
The number to call is +44 (0) 191 203 7010. Lines are open Monday to Friday from 8am to 6pm. Alternatively, you can use our webchat facility which can be found here:
National Insurance: general enquiries  ‘Ask HMRC online’. This facility is available Monday to Friday from 8am to 6pm.
Thank you