I created a Validation Rule to prevent a user to change the record's ownership when is not the owner:
$User.Id <> PriorValue(OwnerId) && ISCHANGED( OwnerId ) It worked.
But I also need any let any user update the ownership in case the current owner is a specific user (user id = '2F0055e000000gdKL').
I tried several ways, but nothing worked. Then I tried to focus only on the specific user validation. It didn't work either:
PriorValue(OwnerId) <> '2F0055e000000gdKL' && ISCHANGED( OwnerId )