TaxBeast

While living and working in USA in 2021 as part of an annual performance bonus my employer granted me restricted company stock in a US brokerage account. The stock would not be available to sell until 3 years later. From the grant date the value of my stock fluctuated and accrued dividends (which automatically reinvested). The stock was "distributed" (i.e. was unlocked in the brokerage account for me to sell) in 2024, when I was back working and living in the UK. The US brokerage account has already withheld a portion of the shares to cover federal tax withholding. My working assumption is that the value of this stock forms part of my remuneration for work performed while living and working in USA, and therefore that is is taxable in USA rather than UK. Sound about right? I've read through HS305 and now I'm more confused than when I started.