X, formerly Twitter, is changing its block policy. With the new policy, blocked users will still be unable to interact with you, but they will be able to view your posts. If you want to keep blocked users from viewing your posts, consider deactivating your account and waiting 30 days for it to be deleted or protect your posts by approving each follower request manually.

Source: https://www.cnet.com/tech/how-to-keep-prying-eyes-off-your-posts-when-x-changes-its-block-policy/#ftag=CAD590a51e