Magento 2 handle’s order increment ids differently than Magento 1. In Magento 1 we used to change the “eav_entity_store” table when we needed to change the prefix. In Magento 2 you will need to change the “sales_sequence_profile” table. This table has the prefix column now. Also there is a “sales_sequence_meta” table which defines the store-specific sequence-tables for the sales entity-types. You will see you now have “sequence_<entity>_<store_id>” tables. These sequence tables contain a record each time the increment id is incremented. These “sequence” tables are automatically created by Magento.