By default, when a maiden name is added to a constituent record, an alias with the record's first name + maiden name is automatically generated and added to the Names tab for the record.
However, some records have an alias with a duplicated maiden name. If a user deletes this alias, enters the constituent in a constituent update batch, and commits the batch without making any changes, the incorrect alias is added back onto the record. For most records, once a specific alias is deleted, the same one will not be automatically re-generated - it can only be manually added on the Names tab by a user.
Download and install the latest patch, which contains all fixes from previous patches. If you are running an older version, download and install the latest version and then the patch.