Different tax years UK vs US

Hi,

 

I filed as a NRA in 2019 but will be filing as a RA for 2020. I am originally from the UK and came to the US in late 2019. The tax year in the UK is April to April. I received a tax refund in the UK in April 2020 for work I did when I was in the UK in 2019.

 

Since this year I will be taxed in the US on my worldwide income, will the UK tax refund in 2020 be taxable in the US, or will it be deemed as income from 2019?