Thank you, I am starting to get it a little more after spending all day trying to.
I have been offered to have my 2021/2021 return updated by an accountancy service, they say this will sort the problem out but I would have thought at least the last 5 years would need to be changed as you need 5 year non resident.
I got through to a technical officer at HMRC, they said to download and complete SA109 going back to 2018/2109 returns on paper documents along with a covering letter. They said as it doesn't affect my tax paid its unlikely there would be any penalty. Form SA109 does seem rather complicated and there does not seem to be much help I have found online, I've printed it all out with the notes and am trying to follow it. Probably will be easier why I have a clear mind.
The officer suggested I may only need to fill in up to Q19, I'm not sure though after reading it, Q18-22 Residence in other countries & Q23-27 I have not understood yet. I've not got as far as Q28-39 Remittance basis. I don't have any other income anywhere, have not been back to the UK so I would have thought it should be straightforward case. I meet the RDR3: Statutory Residence Test automatic test 2.2 "You’ll be non-UK resident for the tax year if you were resident in the UK for none of the 3 tax years before the current tax year, and spend fewer than 46 days in the UK in the tax year.". So maybe I don't need Q18 onwards?
I suppose using an accountant is the easy way out, but I'd like to understand it and have a go myself first.