Hi,

Each operation type in Odoo, such as Receipts, Delivery Orders, or Manufacturing, has its own sequence that controls how documents are numbered. When you confirmed the Sales Order and it created a Manufacturing Order, Odoo used the sequence linked to the operation type instead of the general manufacturing sequence. To fix this, go to Inventory → Configuration → Operation Types, open the operation type used for manufacturing (usually named “Manufacturing”), and check the Sequence field. If it’s pointing to “Sequence In” (with prefix like IN/), change it to your correct manufacturing sequence (with prefix MO/ and code mrp.production). Save the changes, and from now on, any Manufacturing Orders created—whether manually or from a Sales Order will use the proper Manufacturing Order sequence instead of the one from incoming shipments.

Hope it helps.

In general, the Sequence of a Manufacturing Order is determined Reference Sequence of the Operation Type used on that Manufacturing Order which can be found on the resulting Manufacturing Order -> Tab: Miscellaneous -> Operation Type -> Reference Sequence.

Here you can verify whether the correct Operation Type is in use and whether it is set up to your liking.