Capital Gains Tax when Returning to the UK

I have recently returned to the UK and will be a tax resident for the year 2024-25. My last UK tax residency was the year 2020-21, and in between I was a tax resident of a European country. While I was away from the UK, the previous UK company I was working on was sold, and since I had stocks in the company, I received the relevant amount of money from the stock sale. I have returned to the UK before 5 tax years have passed, so according to the HMRC website I would have to pay capital gains tax for the amount coming from the stock sale. Will the capital gains tax be calculated on the tax year that the sale was made, or will it be calculated on the 2024-25 tax year? I am asking because tax allowances have changed between these years.

Hi Kostas,
It is the period you returned to the UK.
Please see details here:
RDRM12660 - Residence: The SRT: Temporary non-residence: Tax when returning to the UK after a period of temporary non-residence
Thank you.