☠️☠️ Possible countdown timer fix ☠️☠️
If anyone is stuck seeing the countdown timer instead of the 'Download' button (due to purchasing another version prior to refunding and buying the Premium version), I've found a fix that's worked for us.
On your PS5, go to Settings - Users and Accounts - Other - Restore licences - OK.
Whilst on that page, click Sign Out.
Restart the PS5.
Sign back in to your PS5 account.
Go to Game Library - Your Collection - then select Sea of Thieves
You should hopefully see 'Download'