If you have made progress on a different platform in Sea of Thieves, please be aware that when linking your Xbox Live account to your PlayStation™Network account, that only certain trophies will unlock automatically for previously completed progress.
This is intended behaviour, as only achievements that can be completed once, such as becoming a Pirate Legend, will sync automatically with your trophies.
If these kinds of trophies are not unlocking, you may need to restart the game a few times for the sync to complete.
Other completed achievements will not unlock the related trophy and so will need to be completed again.
Any progress towards a trophy first made on Xbox, Windows, or Steam will not carry over to PlayStation®5, therefore the requirements for said trophy need to be met from scratch on PlayStation®5. This is due to how trophies are tracked on this platform.