National Insurance gaps

Hi. I am self-employed. I checked my National Insurance record on my account and noticed that I have a 2022-2023 year is not full payment? I don't know why because I paid National Insurance contributions. Where can I check why this is? Where can I find out more about this? Second question I was employed from 2015 to 2017 and earned small amounts of money that my employer didn't have to pay tax on, but didn't they also have to pay National Insurance contributions? On my account all these years are shown as not fully paid. Can I send scans of the documents (P60) to HMRC so they can look at it again, can I have the address, please?

Hi andz5,
In order for us to have a look at your record to investigate tax year 22/23 and the years you were employed that are showing as gaps, please contact the National Insurance Enquiries helpline or Webchat.
Please find out contact details below:
National Insurance: general enquiries
Thank you.