Hi,
The answer to this question depends on the result of the statutory residence tests at RDR3:
RDR3: Statutory Residence Test (SRT) notes
If tax resident in the UK for the whole tax year and split year treatment does not apply, then yes, the capital gain would need to be reported, under the arising basis of taxation. A foreign tax credit of up to 100% of the foreign tax paid, can be claimed.
If split year treatment does apply and the disposal arises before arrival in the UK, then it does not need to be repoted, but can be mentioned as a free hand note, for reference only.
The acquisition value and not the value of the asset on 1 October would be used to calculate any capital gain.
Thank you.