The X platform development account recently announced that they will be discontinuing support for the encryption feature for private messaging for the time being.
They said that the X development team is working on a new message encryption feature that will be introduced in the future, but currently there is no word on when the feature will return.
The encrypted messaging feature on the X platform has only been introduced for messaging between two X users who are subscribed to the X Premium plan, where messages between these two users cannot be accessed by anyone other than those users, including employees and platform supervisors.
X also said that messages that have already been encrypted will remain encrypted, but for the time being, new messages sent will not be encrypted until X introduces the new encryption feature in the future.