There was an issue with the database, since the migration somehow took 200GB extra space, which caused the database on one of the server to go down. The database switched over to its replica, so it works now, but there is a period of 30 mins, where some data will have been lost.

Let me know, if there are any other issues.

EDIT: There does seem to be an issue with creating a post. I will look into it.

EDIT2: Fixed.