There is word on the Official Sea of Thieves Discord from one of the Rare Community Managers and the message is as follows;
DiegoToday at 21:09
@here Ahoy, we are aware of server issues at the moment and are currently investigating. We will update accordingly! Thank you for your patience
More information will be updated as I see or any other players sees more information! :)
Also check out the Support Page for more information