Please note this is a channel-specific article only applicable to Magento 2. Make sure to also check the general troubleshooting steps for Despatch Notes here.
General troubleshooting steps applicable for most or all channels (for details see the article here):
1. The Despatch Notes setting must be enabled before the order is processed.
2. The original items must remain in the order.
3. The order Source channel must be enabled during order processing.
Magento 2 specifics for troubleshooting:
1. Make sure the respective setting is enabled in Settings > Channel integrations > Edit channel details > Order > Despatch Notes. Full details on Magento 2 channel configuration are available here.
2. The status of the orders on the channel will be marked as shipped only if the used Magento 2 version is 2.1.3 or higher.
3. Linnworks have added "limited" support for couriers providing tracking numbers and courier information to Magento. It is limited in that the tracking number and courier name will be provided to Magento no matter which courier is being used. However, Magento 2 will only recognize DHL, FedEx, USPS and UPS. If you are using any other vendor services, Magento 2 will mark the vendor on the order as Custom. The tracking number will still be sent correctly.
In order to get any of the four supported courier names to work on Magento, the services must be mapped in Linnworks Shipping Mapping with the Linnworks Service name specifically being "DHL", "USPS", "UPS" or "FedEx" (case insensitive). Linnworks Service names depend on the Postal Services entries.
Please see the image below as an example:
For Magento 1 Despatch Notes, please see here.